Nausea and Vomiting

Neurologic pathways involved in pathogenesis of nausea and vomiting


57yo male with a history of HTN, DM, and MI s/p stent in 2011 presenting with nausea/vomiting and hypotension. The patient had one episode of non-bloody, non-bilious emesis approximately 6 hours ago. He felt unwell so a friend checked his blood pressure which was found to be 75/50, prompting a visit to this emergency department.
The patient’s emesis came 2 hours following a normal meal (frozen dinner), and was associated with chills/sweats but no abdominal pain. The patient had some associated shortness of breath (baselines), but no chest pain, arm or jaw pain, or palpitations.

He states that these symptoms are unlike what he experienced during his MI. He reported no change in bowel or urinary habits.


  • HTN
  • DM
  • CAD
  • MI
  • Hyperlipidemia


  • Stent placement (2011)
  • Right knee neuroma excision (2012)


  • Non-contributory


  • No current t/e/d
  • 80 pack-year smoking history


  • carvedilol 6.25mg p.o. b.i.d.
  • metformin 1000mg p.o. b.i.d.
  • atorvastatin 20mg p.o. daily
  • aspirin 81mg p.o. daily


  • NKDA

Physical Exam:

VS: T 98.4 HR 65 RR 17 BP 96/56 O2 95% 2L NC
Gen: No acute distress, speaking in complete sentences
HEENT: PERRL, MMM no lesions, no cervical lymphadenopathy
CV: RRR, normal S1/S2, no murmurs, no extra heart sounds, no jugular venous distension
Lungs: CTAB, no crackles
Abd: +BS, soft, NT/ND, no rebound/guarding, no organomegaly
Ext: Warm, well-perfused, peripheral pulses equal b/l, no LE edema
Neuro: AAOx3


  • EKG: normal sinus rhythm, anterior lead q-waves suggestive of old infarct, no T/ST changes
  • Troponin: <0.01
  • CBC: 7.4/15.5/47/228
  • BMP: 139/5.1/107/26/8/1.19/112 (baseline creatinine 1.06 in 2/2013)


  • CXR: no effusion, no cardiomegaly, no focal consolidation
  • Bedside US: normal cardiac wall motion, estimated EF 40-45%, retrohepatic IVC collapses with respiration


57M hx HTN, DM, MI s/p stent presenting with nausea/vomiting x1 and hypotension. The patient’s symptoms and history were concerning for acute myocardial infarction; however, early EKG and troponins were reassuring. Additionally, the absence of characteristic physical findings that would be associated with an acute MI causing cardiogenic shock (elevated JVP, extra heart sounds, pulmonary crackles) were not present. Evidence of end-organ damage was also absent.

Other potential causes for nausea/vomiting include SBO, however, the patient reported normal BM’s and has no history of abdominal surgery. Though occurring after a meal, a single episode of emesis without associated abdominal pain lowers suspicion for biliary disease. This patient’s emesis is most likely due to acute gastroenteritis.

Given the evidence of hypovolemia on bedside ultrasound, the patient was bolused with a total of 1.5L NS and noted symptomatic improvement as well recovery of blood pressure.

Differential Diagnosis of Nausea/Vomiting: 1, 2

A System for Nausea/Vomiting

Pathophysiology: 3, 4, 5

  • Nausea: Sensation associated with increased gastrointestinal motility (tachygastria).
  • Vomiting:
    • Chemoreceptor trigger zone (area postrema of 4th ventricle): sensitive to drugs/toxins (emetics, radiation), neurotransmitters. Located outside BBB.
    • Nucleus tractus solitaries (medulla): pattern generator for vomiting, receives vagal input from GI tract and nociceptive stimuli from peripheral nervous system – transmits to hypothalamus, limbic system and cortex. Stimulated by tickling the back of the throat, gastric distention, and vestibular input.

Important history/physical associations: 4

  • Abdominal pain: suggests organic disease, affected organ dependent on location of pain. (See figure)
  • Abdominal distension: suggests bowel obstruction.
  • Heartburn: suggests GERD.
  • Vertigo/nystagmus: suggests vestibular etiology.
  • Positional/projectile: suggests neurogenic etiology.

Differential Diagnosis of Abdominal Pain By Location:

Abdominal Pain by Location


  1. Scorza, K., Williams, A., Phillips, J. D., & Shaw, J. (2007). Evaluation of nausea and vomiting. American family physician, 76(1), 76–84.
  2. Bork S, Ditkoff J, Hang BS. Chapter 75. Nausea and Vomiting. In: Tintinalli JE, Stapczynski JS, Cline DM, Ma OJ, Cydulka RK, Meckler GD, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York: McGraw-Hill; 2011. Accessed June 15, 2013.
  3. Koch, K. L., Stern, R. M., Vasey, M. W., Seaton, J. F., Demers, L. M., & Harrison, T. S. (1990). Neuroendocrine and gastric myoelectrical responses to illusory self-motion in humans. The American journal of physiology, 258(2 Pt 1), E304–10.
  4. Longstreth, G. F. Approach to the adult with nausea and vomiting. In: UpToDate, Basow, DS (Ed), UpToDate, Waltham, MA, 2013.
  5. Costanzo, L. (2011). Physiology. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins.
  6. Patanwala, A. E., Amini, R., Hays, D. P., & Rosen, P. (2010). Antiemetic therapy for nausea and vomiting in the emergency department. The Journal of emergency medicine, 39(3), 330–336. doi:10.1016/j.jemermed.2009.08.060


Source: Mulpuru, S., Touchie, C., Karpinski, J., & Humphrey-Murto, S. (2010). Coexistent Wegener“s granulomatosis and Goodpasture”s disease. The Journal of rheumatology, 37(8), 1786–1787. doi:10.3899/jrheum.091404

Linear IgG deposits consistent with anti-GBM disease.


“bad cough”


61yo African American female w/hx of HTN presenting with 1mo of persistent cough productive of green-yellow sputum, noticed streaks of blood for the past 5 days. She came to the ED today because she has been feeling increasingly fatigued. She reports subjective fevers at the onset of symptoms which has resolved. She denies shortness of breath, chest pain, chills, night sweats. She sought medical care for this problem 2wk ago and was treated with amoxicillin and a cough suppressant. She recalls a coworker was ill one month ago. She is US-born, had a negative PPD in the past and has no known exposures to tuberculosis.

Of note, the patient reports her urine had a foamy appearance and has been darker in color beginning 3 weeks ago, but this had resolved. She denied dysuria, or frank hematuria.


  • HTN
  • Asthma – last required medications >30yrs ago


  • None


  • Non-contributory


  • No t/e/d
  • Works as librarian


  • benazepril
  • amlodipine
  • amoxicillin
  • promethazine


  • NKDA

Physical Exam:

VS: T 99.4 HR 97 BP 132/60 RR 20 O2 92%
Gen: Well-appearing, pleasant, speaking in complete sentences
HEENT: PERRL, MMM no lesions, no cervical lymphadenopathy
CV: RRR, normal S1/S2, no murmur appreciated
Lungs: Crackles in posterior: right middle/inferior and left inferior fields, no wheezing, no dullness to percussion
Abd: +BS, soft, non-tender, no CVAT
Ext: Warm, well-perfused, 2+ peripheral pulses, 1+ pitting edema to knee
Skin: No lesions on exposed skin
Neuro: AAO


  • CBC: 12.3/6.7/19.8/52.3 (S: 94, B: 1, L: 4, M: 1, MCV: 92.3); baseline Hb/Hct (1/11/2012) 13.4
  • BMP: 136/3.6/101/25/46/3.43/126; baseline creatinine (1/11/2012) 1.18
  • UA: brown, trace LE, – nitrites, 2+ protein, 81 RBC



  • Right mid-lung zone consolidation is present, suggests pneumonia if acute.
  • Mild asymmetric right parenchymal increased density is seen diffusely as well.


65AAF w/hx HTN presents with persistent productive cough, recently with hemoptysis.

# Cough: Symptoms and physical findings of abnormal breath sounds (crackles, though no strict consolidation) concerning for community-acquired pneumonia. Addition of hemoptysis raises concern for TB, particularly when taking into consideration the duration of cough and presence of constitutional symptoms. CBC shows leukocytosis with left shift, CXR with right mid/lower lob infiltrates consistent with pneumonia. Recommend admission and isolation to rule out TB, start empiric therapy for community acquired pneumonia with ceftriaxone, azithromycin. Obtain induced sputum samples for culture, AFB smear and culture.

# Abnormal urine: Patient describes changes in urine suggestive of proteinuria and hematuria. Acuity of onset and apparent spontaneous resolution suggests a chronic kidney injury 2/2 hypertension is unlikely. Absence of dysuria, or tenderness (suprapubic, costovertebral) suggests complicated UTI unlikely. Urinalysis notable for 2+ protein and significant RBC’s, possible nephritic syndrome. In the setting of hemoptysis, this raises concern for anti-GBM disease vs. vasculitis.

# Anemia: Normocytic anemia. No evidence of acute, life-threatening hemorrhage as patient is currently hemodynamically stable. Possible sites of blood loss include alveoli, glomeruli. Given that patient sought care today for worsening fatigue, will monitor hemoglobin closely and consider transfusion. Obtain iron studies.

# HTN: BP stable, hold home medications.

Interval History:

The patient was admitted for management of community-acquired pneumonia and isolation to rule out TB. Empiric therapy with CTX + azithromycin was continued. On HOD1, the patient was transfused two units of PRBC’s. On HOD2, the patient underwent CT chest/abdomen/pelvis due to worsening respiratory status despite antimicrobial therapy. On HOD3, the patient went into atrial fibrillation with RVR which was converted to sinus rhythm with metoprolol 5mg IV x3. On HOD5, nephrology consult recommended starting steroid therapy, plasmapheresis and obtaining a renal biopsy, however the biopsy was delayed due to worsening respiratory status.

Interval Labs:

  • Iron studies: Fe 8, TIBC 203, Ferritin 468, haptoglobin 333, retics 2.7
  • Inflammatory markers: ESR 120, CRP 34
  • Micro: BCx NGTD, RCx moderate Candida, sputum AFB smear negative x3
  • LFT: AST 34, ALT 29, ALP 52, protein 6.3, albumin 2.4, T.bil 0.8, D.bil 0.2
  • Quant-gold: negative
  • Anti-GBM 1.2 (nl <1.0)
  • p-ANCA: positive 1:640, [ELISA pending]
  • ANA: positive 1:320, speckled
  • HIV: negative

Interval Imaging:

CT Chest

  • Diffuse right lung, tree and bud opacities, ground-glass opacities and areas of confluence with scattered air bronchograms. Less severe similar pattern in the left lung as well particular at the base.
  • Right paratracheal, subcarinal and perihilar LAD.
  • Findings concerning for primary TB in the right clinical setting. DDx nonspecific bacterial PNA and fungal PNA.

CT Abdomen/Pelvis

  • Mild nonspecific R > L perinephric stranding.

Interval Assessment/Plan:

# Acute respiratory failure: Unlikely simple CA-PNA given worsening status while on appropriate antibiotic therapy. Active tuberculosis possible given history of chronic productive cough with hemoptysis, constitutional symptoms and imaging findings. IGRA’s of limited utility in diagnosis of active disease, further, while three negative sputum AFB smears decreases the likelihood of TB, additional testing with NAAT and culture is required. Another possibility is a vasculitic process given concomitant hematuria and acute renal failure, with respiratory symptoms now 2/2 alveolar hemorrhage. This was evaluated with ANCA assay which was positive for p-ANCA with high titer. This is often suggestive of primary vasculitis (in this case likely microscopic polyangiitis vs. Churg-Strauss), however ELISA for target antigen is of particular importance as p-ANCA with specificity for antigens other than MPO can be associated with another condition on the differential: Goodpasture’s syndrome. This patient was found to have elevated anti-GBM antibodies which are highly suggestive of Goodpasture’s syndrome, and can be associated with ANCA-positivity (often suggesting a poorer prognosis with decreased likelihood of recovery of renal function).1

# Acute kidney injury: The patient had significant elevation of serum creatinine compared to last-recorded baseline. She also described darkening and foamy appearance of urine 3 weeks prior to admission, suggestive of proteinuria/hematuria of relatively acute onset. This was supported by urinalysis findings of protein and RBC’s (with casts). Given presence of anti-GBM antibodies, high specificity of such findings, and correlation with glomerulonephritis with evidence of pulmonary alveolar hemorrhage, this appears to be the most likely cause at this time. Definitive diagnosis with renal biopsy to be obtained following stabilization of respiratory status. Patient will be started on plasmapheresis and immunosuppressive therapy (corticosteroids, cyclophosphamide).

# Normocytic Anemia: Likely combination of acute blood loss (2/2 hematuria, pulmonary alveolar hemorrhage) and chronic disease. Normocytic anemia with some reticulocytosis suggestive of acute blood loss, however iron studies with low Fe, TIBC and elevated ferritin suggest chronic disease as an associated factor.

Differential Diagnosis of Hemoptysis: 2, 3

A System for Hemoptysis

A System for the Diagnosis of Tuberculosis: 4, 5

A System for the Diagnosis of Tuberculosis


A System for Vasculitides: 8, 9

A System for Vasculitidies


Vasculitis Mimics: 9

Vasculitis Mimics


Interpretation of antineutrophil cytoplasmic autoantibodies (ANCA): 10

Pattern Target Associated vasculitis Other diseases
  • Granulomatosis with polangiitis (Wegener’s)
  • Eosinophilic granulomatosis with polyangiitis (Churg-Strauss)
  • Microscopic polyangiitis
  • Pauci-immune glomerulonephritis
C-ANCA (atypical) BPIMPO
  • IBD
  • Cystic fibrosis


  • Microscopic polyangiitis
  • Eosinophilic granulomatosis with polyangiitis (Churg-Strauss)
  • Pauci-immune glomerulonephritis
  • Autoimmune hepatitis
  • IBD, PSC
  • SLE, RA
  • Drugs
  • Infection (HIV, fungal)

Differential Diagnosis of Anemias: 11

A System for Anemias


  1. Levy, J. B., Hammad, T., Coulthart, A., Dougan, T., & Pusey, C. D. (2004). Clinical features and outcome of patients with both ANCA and anti-GBM antibodies. Kidney international, 66(4), 1535–1540. doi:10.1111/j.1523-1755.2004.00917.x
  2. Bidwell, J. L., & Pachner, R. W. (2005). Hemoptysis: diagnosis and management. American family physician, 72(7), 1253–1260.
  3. Hirshberg, B., Biran, I., Glazer, M., & Kramer, M. R. (1997). Hemoptysis: etiology, evaluation, and outcome in a tertiary referral hospital. Chest, 112(2), 440–444. doi:10.1378/chest.112.2.440
  4. Campbell, I. A., & Bah-Sow, O. (2006). Pulmonary tuberculosis: diagnosis and treatment. BMJ (Clinical research ed.), 332(7551), 1194–1197. doi:10.1136/bmj.332.7551.1194
  5. Zumla, A., Raviglione, M., Hafner, R., & Reyn, von, C. F. (2013). Tuberculosis. The New England journal of medicine, 368(8), 745–755. doi:10.1056/NEJMra1200894
  6. Diagnostic Standards and Classification of Tuberculosis in Adults and Children. American journal of respiratory and critical care medicine. doi:10.1164/ajrccm.161.4.16141
  7. Laraque, F., Griggs, A., Slopen, M., & Munsiff, S. S. (2009). Performance of nucleic acid amplification tests for diagnosis of tuberculosis in a large urban setting. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 49(1), 46–54. doi:10.1086/599037
  8. Gross, W. L., Trabandt, A., & Reinhold-Keller, E. (2000). Diagnosis and evaluation of vasculitis. Rheumatology (Oxford, England), 39(3), 245–252.
  9. Suresh, E. (2006). Diagnostic approach to patients with suspected vasculitis. Postgraduate medical journal, 82(970), 483–488. doi:10.1136/pgmj.2005.042648
  10. Rus, V., & Handwerger, B. S. (2000). Clinical value of antineutrophil cytoplasmic antibodies. Current rheumatology reports, 2(5), 383–389.
  11. Goljan, E. (2011). Pathology. Philadelphia, PA: Mosby/Elsevier.

Small Bowel Obstruction

Dilated loops of small bowelCC:

Consultation for bowel obstruction


The patient is a 40yo male with a history of alcohol abuse, and seizure disorder secondary to traumatic brain injury who was admitted to this hospital 4d ago after an altercation with law enforcement officials. On arrival, the patient was reported to be acutely intoxicated with ecchymosis and bleeding from left lateral/posterior head and ear. No other significant injuries were found and the patient underwent CT imaging of head and c-spine, with notable findings of left occipital epidural hematoma, subarachnoid hemorrhage, but no significant midline shift. Neurosurgery was consulted and no emergent surgical intervention was required, the patient underwent serial imaging to monitor the bleed which was found to be stable and the patient slowly returned to baseline mental status.

On HOD4, the patient developed nausea/vomiting and abdominal pain, a nasogastric tube was placed with feculent output. CT abdomen/pelvis showed high grade SBO and possible mesenteric ischemia/infarct, and general surgery was consulted for further evaluation. The patient reported experiencing some abdominal pain since the altercation, but could not recall if he was hit in the abdomen.


  • Alcohol abuse
  • Seizure disorder


  • Tibia fracture
  • No prior abdominal surgery


  • Non-contributory


  • Current alcohol, marijuana use, no tobacco use
  • History of homelessness


  • Norco PRN
  • Ativan PRN
  • LISS, SQH, Thiamine
  • NKDA

Physical Exam:

  • VS:  T 99.5°F    HR 108    RR 16    BP 128/82    O2 99% RA
  • Gen: NAD
  • HEENT: PERRL, EOMI, sclera clear, anicteric
  • CV: RRR, normal S1/S2
  • Lungs: CTAB
  • Abd: Distended, diffuse tenderness to palpation, no rebound tenderness, no ecchymoses or signs of trauma
  • Ext: Warm, well-perfused
  • Neuro: AAOx4, appropriate


40M w/hx alcohol abuse, TBI and seizure disorder, presented initially with evidence of head trauma which was stabilized. However, the development of abdominal pain, N/V, and finding of distension on exam associated with copious output of feculent material from NGT suggests bowel obstruction. This patient has no history of abdominal surgeries to suggest adhesions as a possible cause. Though the patient cannot recall any abdominal trauma, and there was no e/o trauma on exam, findings on CT abdomen/pelvis are suggestive of traumatic cause (hematoma causing obstruction or ischemia resulting from mesenteric injury). The patient was monitored for several days, continuing NGT to suction and with serial abdominal films. However, abdominal pain persisted, abdominal radiographs showed worsening obstruction and the patient developed leukocytosis and on HOD7 the patient was taken to the OR for exploratory laparotomy. Upon entering the peritoneal cavity, there was obvious blood and very distended small bowel which was run distally with finding of a mesenteric laceration in the distal ileum which was walled off by omentum. Additionally, a grade 2 splenic laceration was found. Ultimately, a small bowel resection with primary anastomosis along with a repair of the splenic laceration was performed.


CT abdomen/pelvis

CT abdomen/pelvis

Moderate abdominal and pelvic ascites which has Hounsfield unit attenuation is greater than simple fluid suggestive of blood products.

CT abdomen/pelvis

CT abdomen/pelvis

Fluid dilated small bowel

CT abdomen/pelvis

CT abdomen/pelvis

Complex transition point in the central mid abdomen.
Segment of bowel at the transition point has circumferential mural thickening and surrounding complex attenuation mesenteric fluid and mesenteric stranding.

Abdominal X-Ray

Abdominal X-Ray

Small bowel distention
Nasogastric tube is seen coiled in the gastric fundus

CT Head

CT Head

Left occipital extracranial soft tissue hematoma
Left occipital epidural hematoma subjacent to the fracture site in addition to subarachnoid hemorrhage within the sulci of the left temporal lobe and interpeduncular cistern
Extra-axial fluid collection along the right frontal convexity, tracking down the anterior falx, compatible with a subdural hematoma

Differential Diagnosis for bowel obstruction: 1, 2, 3

A System for Bowel Obstruction

Types of Abdominal Pain: 4

Types of Abdominal Pain


  1. Kulaylat MN, Doerr RJ. Small bowel obstruction. In: Holzheimer RG, Mannick JA, editors. Surgical Treatment: Evidence-Based and Problem-Oriented. Munich: Zuckschwerdt; 2001. Available from:
  2. Jackson, P. G., & Raiji, M. T. (2011). Evaluation and management of intestinal obstruction. American family physician, 83(2), 159–165.
  3. Maung, A. A., Johnson, D. C., Piper, G. L., Barbosa, R. R., Rowell, S. E., Bokhari, F., Collins, J. N., et al. (2012). Evaluation and management of small-bowel obstruction. Journal of Trauma and Acute Care Surgery, 73, S362–S369. doi:10.1097/TA.0b013e31827019de
  4. Stabile, Bruce. “The Acute Abdomen.” Chairman’s Hour. Harbor UCLA Department of Surgery Student Lecture Series. 5/17/13. Lecture.

Abdominal Wall Hernias

Inguinal hernia CTHPI:

23M w/no known medical history presenting with abdominal “ball” x10d. Patient denies pain, and is tolerating regular diet w/o N/V. Reports lifting weights.


None, non-contributory, no t/e/d.


Acetaminophen, NKDA


  • VS:     T N/A      HR 86     RR 18       BP 116/64      O2 N/A
  • Gen: Well-appearing young male, no acute distress
  • HEENT: PERRL, MMM no lesions
  • CV: RRR, normal S1/S2, no murmurs
  • Lungs: CTAB, no crackles/wheezes
  • Abd: +BS, soft, NT/ND, 3cm bulge in right inguinal region with valsalva, above inguinal ligament, ~7cm lateral to symphysis, non-tender, reduces spontaneously after valsalva GU: uncircumcised penis, testes descended b/l, normal size, non-tender, no herniation through inguinal canal palpated with valsalva
  • Ext: Warm, well-perfused, 2+ peripheral pulses
  • Neuro: Alert and oriented, appropriate


23M ċ inguinal hernia, currently asymptomatic with no evidence of incarceration/strangulation. Recommend follow-up at city hospital for evaluation and possible surgical repair. Advised to refrain from strenuous activity, heavy lifting.

Physical Examination Techniques: 1

Physical Examination Techniques

  • Observation: Best performed with patient standing and physician seated on a stool facing the patient
  • Palpation: place hand over patient’s groin (see figure), with two fingers each superior and inferior to the inguinal ligament. Have the patient cough and feel for a palpable bulge or impulse.
  • GU: With a finger in the inguinal canal, bulges felt against the side of the examining finger are direct hernias, while those felt at the tip of the finger are indirect.

Types of Abdominal Wall Hernias: 2

Types of abdominal wall hernias

Name Location Etiology/Epidemiology
1. Umbilical Linea alba through weakened umbilical ring.Paraumbilical hernias through linea alba in the region of the umbilicus. Congenital or acquired due to increased intra-abdominal pressure (obesity, pregnancy, ascites, PD)
2. Epigastric Linea alba between umbilicus and xiphoid process Congenital weakness of linea alba (lack of decussating fibers)
3. Spigelian Semilunar line: along the lateral borders of rectus abdominus. Herniation typically occurs caudally (below arcuate line) due to absence of posterior rectus sheath.
4. Incisional Site of prior incision Poor fascial healing possibly due to: infection (increased risk in wound dehiscence), obesity, smoking, immunosuppression excess wound tension, CT disorders.
5. Inguinal Indirect: internal (deep) inguinal ring, lateral to inferior epigastric vessels.Direct: external (superficial) inguinal ring, medial to inferior epigastric vessels. Indirect > direct.
6. Femoral Inferior to the inguinal ligament, through empty space medial to femoral sheath. F > M, increased likelihood of incarceration/strangulation (40%)
7. Lumbar 3 Arise in two anatomical triangles:Superior lumbar triangle – lateral border internal oblique, medial border erector spinae, superior border 12thrib.Inferior lumbar triangle – lateral border external oblique, medial border latissimus dorsi, inferior border iliac crest. (See figure) Associated with surgery (incisional), typically urologic.
8. Obturator Protrusion of peritoneal sac through obturator foramen. Rare, occur primarily in elderly women (high predisposition for incarceration).

Locations of Abdominal Wall Hernias:

Locations of abdominal wall hernias

Layers of the Anterior Abdominal Wall:


Differential diagnosis for groin masses: 4

Category Inguinal 5 Scrotal 6 Vulvar 7 Perineal 8
Vascular Varicocele extension Varicocele Vulvar varicocity

Infectious, Inflammatory Lymphadenopathy
Inflammatory joint process (hip, related bursae)
Bartholin’s cyst
Neoplastic Benign (lipoma)
Lymph node metastatsis
Testicular malignancy Malignant skin lesions Soft-tissue malignancy
Anal SCC
Rectal GIST
Metastasis (commonly anorectal, prostatic)
Congenital, Anatomic Hernia
Testis (undescended, retracted)
Epididymal cyst
Embryological remnants (mucocele)
Traumatic Hematoma
Aneurysm (complication of catheterization)
Hematoma Hematoma

Locations of Groin Masses: 9

Locations of groin masses


  1. Amerson JR. Inguinal Canal and Hernia Examination. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 96. Available from:
  2. Aguirre, D. A., Casola, G., & Sirlin, C. (2004). Abdominal Wall Hernias: MDCT Findings. American Journal of Roentgenology, 183(3), 681–690. doi:10.2214/ajr.183.3.1830681
  3. Guillem, P., Czarnecki, E., Duval, G., Bounoua, F., & Fontaine, C. (2002). Lumbar hernia: anatomical route assessed by computed tomography. Surgical and radiologic anatomy : SRA, 24(1), 53–56.
  4. Roberts, J. R., & Hedges, J. R. (2010). Clinical procedures in emergency medicine. (5th ed., Vol. section 7, p. Ch. 44). W B Saunders Co. Retrieved from
  5. Shadbolt, C. L., Heinze, S. B., & Dietrich, R. B. (2001). Imaging of groin masses: inguinal anatomy and pathologic conditions revisited. Radiographics : a review publication of the Radiological Society of North America, Inc, 21 Spec No, S261–71.
  6. Eyre, RC. Evaluation of nonacute scrotal pathology in adult men. In: UpToDate, Rose, BD (Ed), UpToDate, Waltham, MA, 2013.
  7. Foster, D. C. (2002). Vulvar disease. Obstetrics and gynecology, 100(1), 145–163.
  8. Tappouni, R. F., Sarwani, N. I., Tice, J. G., & Chamarthi, S. (2011). Imaging of unusual perineal masses. American Journal of Roentgenology, 196(4), W412–20. doi:10.2214/AJR.10.4728
  9. Collins, R. (2008). Differential diagnosis in primary care. Philadelphia: Lippincott Williams & Wilkins.

Acute Diarrhea (in developing countries)

A clinic near JalapaHPI:

1yo M, ex-term, previously healthy, with 8d tactile fever/diarrhea, initially watery, presenting now due to bloody diarrhea x1d. Mother reports 8-10 episodes/day, decreased PO intake and urine output x4d and changes in behavior (lethargy, irritability). No vomiting, no e/o abdominal pain, no cough, no seizures, no weight loss, no known sick contacts.


  • Full term
  • No perinatal complications
  • Vaccination history unknown


  • Meeting all developmental milestones
  • No sick contacts



Physical Exam:

  • VS:   HR 135    BP 86/60    RR 24    T N/A    Wt 11kg (60%)
  • General: Patient was initially examined after initial rehydration with IVF. Well-appearing child, interactive and smiling.
  • HEENT: NC/AT, PERRL, MMM no lesions, no nuchal rigidity
  • CV: RRR, normal S1/S2
  • Lungs: CTAB
  • Abd: +BS, soft, NT/ND, no rebound/guarding
  • Ext: Warm, well-perfused, 2+ peripheral pulses (radial, DP, PT), capillary refill <2s
  • Skin: No visible skin lesions
  • Neuro: Alert and responsive


1yo healthy male with fever, bloody diarrhea and history consistent with dehydration. Most likely cause of acute diarrhea in this patient is infectious, particularly Shigella spp given presence of blood. Other concerning causes of diarrhea in this patient with reports of fever and changes in mental status include a serious bacterial illness (meningitis, pneumonia, UTI), however, these are less likely given the predominant, voluminous diarrhea and absence of symptoms associated with each. Other considerations include appendicitis, volvulus, intussusception, however again copious diarrhea in association with a benign abdominal exam makes these causes less likely. Early presentation of chronic diarrhea cannot be ruled out, however unlikely given association with fever and local prevalence of infectious causes.

Management included IV rehydration, followed by maintenance with PO ORS, early nutritional support, and ciprofloxacin 15mg/kg IV q12h.

Types and causes of acute diarrhea: 1, 2

Types and Causes of Acute Diarrhea

Assessment of Hydration Status


Dehydration Level

Variable/Sign Mild (3-5%) Moderate (6-9%) Severe (>10%)
General appearance Restless, alert Drowsy, postural hypotension Limp, cold, sweaty, cyanotic extremities
Radial pulse Normal rate, strength Rapid, weak Rapid, thready, sometimes impalpable
Respiration* Normal Deep Deep and rapid
Anterior fontanelle Normal Sunken Very sunken
SBP Normal Normal or low Low
Capillary refill* Normal (<2s) Prolonged (2-4s) Markedly prolonged (>4s)
Skin turgor* Normal Pinch retracts slowly Pinch retracts very slowly
Eyes Normal Sunken Grossly sunken
Tears Present Absent Absent
Mucous membranes Moist Dry Very Dry

* = sensitivity > 70% 3,4

Management of Acute Diarrhea: 5,6

Management of Acute Diarrhea

Pathogens causing diarrhea: 6

Pathogen Epidemiology/Transmission Comments Incubation Fever Abd. pain N/V Bloody stool Stool WBC Stool Heme
S. aureus, B. cereus Food poisoning with preformed toxin Vomiting > diarrhea 1-6h X X X X
C. perfringens Spores germinate in meats, poultry 6-24h X X X X
Norovirus Winter outbreaks in schools, nursing homes, cruise ships Adults: diarrhea

Children: vomiting

1-2d X X X
Rotavirus #1 MCC children Vaccine available 1-2d X X X
Campylobacter #1 MCC invasive enterocolitis in US

Undercooked poultry

GBS 2-5d
Salmonella #2 MCC enterocolitis in US Outbreaks

Undercooked egg, dairy, poultry

Shigella Community-acquired, person-to-person 1-3d
EIEC Outbreaks

Undercooked beef, raw seed sprouts

Produces Shiga toxin 1-8d
C. difficile Nosocomial Leukocytosis X
E. histolytica Travel to tropical regions
Giardia Day care, waterborne transmission 1-3d X X X X
Vibrio Contaminated water, seafood 1-3d
Yersinia Foodborne transmission Mesenteric lympadenitis (simulates acute appendicitis) 1-3d


  1. Huilan, S., Zhen, L. G., Mathan, M. M., Mathew, M. M., Olarte, J., Espejo, R., Khin Maung, U., et al. (1991). Etiology of acute diarrhoea among children in developing countries: a multicentre study in five countries. Bulletin of the World Health Organization, 69(5), 549–555.
  2. Navaneethan, U., & Giannella, R. A. (2008). Mechanisms of infectious diarrhea. Nature clinical practice. Gastroenterology & hepatology, 5(11), 637–647. doi:10.1038/ncpgasthep1264
  3. Steiner, M. J., DeWalt, D. A., & Byerley, J. S. (2004). Is this child dehydrated? JAMA : the journal of the American Medical Association, 291(22), 2746–2754. doi:10.1001/jama.291.22.2746
  4. Gorelick, M. H., Shaw, K. N., & Murphy, K. O. (1997). Validity and reliability of clinical signs in the diagnosis of dehydration in children. Pediatrics, 99(5), E6.
  5. Harris, JB, Pietroni M. Approach to the child with acute diarrhea in developing countries. In: UpToDate, Basow, DS (Ed), UpToDate, Waltham, MA, 2013.
  6. Thielman, N. M., & Guerrant, R. L. (2004). Clinical practice. Acute infectious diarrhea. The New England journal of medicine, 350(1), 38–47. doi:10.1056/NEJMcp031534

A System for Differential Diagnosis

Given the objective of this site – namely to approach the evaluation of patients in a systematic fashion – I thought it would be useful to put some thought into how best to develop these systems. The method I’ll detail below might be cumbersome to apply in every situation, but (at this point at least) it is the best way to ensure that nothing is overlooked.

A System for Differential Diagnosis:

A system for systems

Any illness or abnormality for which a patient could seek medical attention (or a colleague, consultation) can be broadly encompassed by the statement above. The differential diagnosis is developed by delineating the chief concern(s) or primary aberrant signs, and selecting a relevant mixture of disease processes and organ systems. The differential can be narrowed by determining subjective and objective details surrounding the chief concern. The differential can be broadened by expanding each major category into subcategories.


  1. Benbassat, J., & Bachar-Bassan, E. (1984). A comparison of initial diagnostic hypotheses of medical students and internists. Journal of medical education, 59(12), 951–956.
  2. Bowen, J. L. (2006). Educational strategies to promote clinical diagnostic reasoning. The New England journal of medicine, 355(21), 2217–2225. doi:10.1056/NEJMra054782
  3. Coderre, S., Mandin, H., Harasym, P. H., & Fick, G. H. (2003). Diagnostic reasoning strategies and diagnostic success. Medical education, 37(8), 695–703.
  4. Fulop, M. (1985). Teaching differential diagnosis to beginning clinical students. The American journal of medicine, 79(6), 745–749.
  5. Graber, M. L., Tompkins, D., & Holland, J. J. (2009). Resources medical students use to derive a differential diagnosis. Medical teacher, 31(6), 522–527.
  6. Sapira, J. D. (1981). Diagnostic strategies. Southern medical journal, 74(5), 582–584.

Gastosin Ingestion

Jalapa, NicaraguaCC:

“Gastosin” ingestion


29F BIB family after patient was found down at home, near opened bottle of Gastosin in presumed suicide attempt. On arrival to ED, patient was awake, but unresponsive, groaning and clutching stomach. GCS  was E3-V2-M5, HR 110, BP 60/palp, RR 24.

ED Course:

Upon arrival, placed two large-bore IV w/rapid infusion of 2L NS and given DA 2g IV x2. NG tube placed, initiated lavage of gastric contents with NS. Patient’s mental status continued to deteriorate, became unresponsive.




History of alcohol abuse and depression per family.


  • VS: 110bpm, 60/palp, 24 R/min, no temp/O2sat available
  • General: Ill-appearing female, laying on bed in considerable distress, groaning and clutching stomach, diaphoretic
  • HEENT: NC/AT, PERRL (4-3mm), EOMI, MMM no lesions, no tongue lacerations, breath with foul odor, TM’s clear b/l.
  • CV: RRR, normal S1/S2, tachycardia, faint heart sounds, JVP elevated though patient supine
  • Lungs: CTAB, no crackles/wheezes
  • Abdomen: +BS, soft, non-distended, no guarding, no ecchymosis
  • GU: Normal external genitalia, loss of stool noted.
  • Neuro: Patient confused, initially responsive to sternal rub, moving all 4 extremities spontaneously/equally, EOMI without nystagmus, gag reflex present, DTR 2+ and symmetric throughout with toes downgoing.
  • Extremities: Cool, peripheral pulses 0 (radial, PT, DP), 1+ (femoral, brachial, carotid)1, capillary refill 3sec
  • Skin: No visible skin lesions

Assessment & Plan:

29F, unknown PMH, ċ ingestion of unknown amount of “Gastosin”. Patient presenting in likely cardiogenic shock given hypotension with reflex sympathetic activation (evidenced by peripheral vasoconstriction à cool extremities, diaphoresis) and no evidence of hemorrhage. Gastosin is a pesticide used in the storage of maize2, and is well-known locally as a common agent in self-poisonings. Chemically composed of aluminum phosphide, and liberates phosphine gas on exposure to moisture which is rapidly absorbed by inhalation, transdermally or gastrointestinally. Toxicity results from free radical damage and inhibition of enzymes of metabolism (particularly affecting cardiac myocytes). Clinical features include vomiting, resistant hypotension and metabolic acidosis.3

Patient’s symptoms and presentation are consistent with cardiogenic shock secondary to Gastosin ingestion. Management included fluid resuscitation and inotropic support with dopamine, as well as gastric lavage. Resuscitation efforts were unsuccessful and patient remained hypotensive with worsening of mental status, and eventual death.

Differential Diagnosis for Shock:

A System for Shock

A System for the Management of Aluminum Phosphide Poisoning:4,5

Management of Aluminum Phosphide Poisoning

The Glasgow Coma Scale:

  Eye Opening Best Motor Response Best Verbal Response
1 None None None
2 Pain Extension Groans
3 Verbal Flexion Unintelligible
4 Open Withdraws Disoriented
5 Localizes Oriented
6 Obeys commands


  1. Hill RD, Smith RB III. Examination of the Extremities: Pulses, Bruits, and Phlebitis. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 30. Available from:
  2. Udoh, J., Ikotun, T., & Cardwell, K. (n.d.). Storage systems for maize (zea mays l.) in nigeria from five agro-ecological zones. Proceedings of the 6th International Working Conference on Stored-product Protection, 2, 960-965.
  3. Bogle, R. G., Theron, P., Brooks, P., Dargan, P. I., & Redhead, J. (2006). Aluminium phosphide poisoning. Emergency medicine journal : EMJ, 23(1), e3. doi:10.1136/emj.2004.015941
  4. Gurjar, M., Baronia, A. K., Azim, A., & Sharma, K. (2011). Managing aluminum phosphide poisonings. Journal of Emergencies, Trauma, and Shock, 4(3), 378–384. doi:10.4103/0974-2700.83868
  5. Jones, A. L., & Volans, G. (1999). Management of self poisoning. BMJ (Clinical research ed.), 319(7222), 1414–1417.

Skull Fracture

Frontal bone fractureID:

14 year-old female, previously healthy, brought in by ambulance s/p auto vs. pedestrian.


Incident unwitnessed, paramedics report no LOC with GCS 15 at scene. GCS 10 upon arrival to ED, with 2min GTC seizure. Patient intubated for airway protection and CT head showed non-displaced frontal bone fracture and small frontal SAH. Patient self-extubated, returned to baseline mental status and was transferred to PICU.


  • VS: 128/76mmHg, 120bpm, 22 R/min, 100% RA, 37.6°C
  • General: Alert and responsive young female with multiple bandages on extremities
  • HEENT: Right frontal hematoma, no bony defect palpated, multiple facial abrasions, no otorrhea, no rhinorrhea, TM clear b/l, no other ecchymosis.
  • CV: RRR, normal S1/S2, no M/R/G
  • Lungs: CTAB
  • Abdomen: +BS, soft, NT/ND, no rebound/guarding, no flank ecchymoses
  • Neuro: AAOx3, CN II-XII intact, sensation/motor/reflexes symmetric and intact.
  • Extremities: Well-perfused with good pulses, no focal bony tenderness, no joint effusions, multiple abrasions on extensor surfaces of all four extremities.

Assessment & Plan:

14yo female, previously healthy, s/p auto vs. peds followed by GTC seizure and CT head showing small SAH and non-displaced frontal bone skull fracture. No evidence of basilar skull fracture on examination or imaging. Seizure likely 2/2 irritation from SAH. Patient was followed closely in PICU with q1h neuro checks with low threshold for repeat CT if change in mental status or more seizures occurred. The patient was eventually transferred to the general ward and was discharged with neurology follow-up and Keppra for seizure prophylaxis for 6mo.

Types of Skull Fractures:

A system for skull fractures

Failure to Thrive

Failure to ThriveID:

5mo female with a history of multiple food allergies, GERD and FTT admitted from clinic for persistent failure to gain weight.


The patient’s mother states that the current diet is 3oz of Neocate 20cal/oz q3h, and that the baby sleeps through the night. The child has a history of reflux, but no emesis in the past few weeks since starting Reglan. There was a history of bloody diarrhea, however none since age 2mo after a change of formula. Mother reports known allergies to milk, soy, protein, and egg. No recent fevers/chills, emesis, diarrhea, fussiness.

The patient was born at 27wks via emergency Cesarean for non-reassuring fetal heart tracings, was intubated in the DR and remained in the NICU for one week.


  • VS: 98/65mmHg, 114bpm, 98.1°, 33/min, 100% RA
  • Gen: Small for age, smiling and interactive
  • HEENT: PERRL, MMM, no lesions
  • CV: RRR, no M/R/G, Lungs: CTAB
  • Abdomen: +BS, soft, NT/ND, no masses, no hepatosplenomegaly
  • Ext: Normal capillary refill

Assessment & Plan:

5mo female, ex-27wks with a history of multiple food allergies, GERD, FTT. Persistent failure to gain weight, admitted for evaluation of feeding habits and observed weight gain. The patient was determined to not be receiving adequate intake and was advanced to a high-calorie formula and parental education was provided. After two days of observed (and appropriate) weight gain, the patient was discharged with follow-up at multiple specialty clinics including GI, FTT, and A&I.

Differential Diagnosis for Failure to Thrive:

A System for Failure to Thrive


Quick Case: Pleuritic Chest Pain

Image from: Maeng, C. H., Chin, S. O., Yang, B. H., Kim, S.-Y., Youn, H.-J., Cho, K. S., Baek, S. K., et al. (2007). A case of organizing pneumonia associated with rituximab. Cancer research and treatment : official journal of Korean Cancer Association, 39(2), 88–91. doi:10.4143/crt.2007.39.2.88

30yo male presenting with forearm cellulitis, also complaining of right-sided sharp chest pain worse with deep inspiration and some movements of the ipsilateral shoulder. Found to have multiple pulmonary nodules (suggestive of metastasis) with the largest being a subpleural nodule in the superior/anterior portion of the RUL (roughly the location of the patient’s pain).


Differential Diagnosis of Pleuritic Chest Pain

Causes of Pleuritic CP

Location of Referred Pain

Referred Pain


Sore Throat

Oropharynx AnatomyID:

17 year-old female presenting to the pediatric ED with sore throat for 2 days.


The patient reports steadily worsening sore throat over the past 2 days, associated with a sensation of swelling. The pain is described as sharp, 4/10 in severity, located on the left side of her throat, and worsened with swallowing. She denies inability to swallow or difficulty breathing, she also denies fever, cough, new skin rashes or genital lesions.

She has no PMH/PSH, takes no medications, denies t/e/d use and is not currently sexually active.


  • VS: 111/65mmHg, 80bpm, 97.8°, 16/min, 100% RA
  • Gen: Well-appearing, NAD
  • HEENT: PERRL, no conjunctival injection, TM clear b/l, minimal pharyngeal erythema on left with 6mm white circular lesion on left tonsil, no tonsillar enlargement, no uvular deviation, no cervical LAD, neck supple no masses, normal neck ROM
  • CV: RRR, no M/R/G, Lungs: CTAB
  • Abdomen: +BS, soft, NT/ND
  • Ext: Warm, well-perfused, normal peripheral pulses

Assessment & Plan:

17yo female with no significant PMH with acute pharyngitis for 2 days. The most likely cause of the patient’s symptoms is viral pharyngitis, potentially herpangina (given the appearance of the tonsillar lesion). A more serious viral/bacterial pharyngitis is less likely given the absence of fever or significant erythema/exudate. There was no uvular deviation to suggest peritonsillar abscess and no evidence of airway obstruction to suggest other acute processes (epiglottitis, retropharyngeal abscess). The plan is to recommend supportive care and ibuprofen for symptomatic relief. The patient will be discharged home in good condition with precautions to return if symptoms worsen or she begins to have difficulty swallowing/breathing.

Differential Diagnosis of Acute Pharyngitis:

Acute Pharyngitis


Evaluation (history):

  • Respiratory distress: epiglottitis, retropharyngeal abscess, peritonsillar abscess, EBV (obstruction in or near pharynx)
  • Fatigue: infectious mononucleuosis
  • Abrupt onset: epiglottitis

Evaluation (physical examination):

  • Vesicles anterior: herpetic stomatitis, SJS, Behcet
  • Vesicles posterior: herpangina (± involvement of extremities)
  • Asymmetry: peritonsillar abscess
  • Stridor, drooling, respiratory distress: airway obstruction
  • Generalized inflammation: Kawasaki

Pediatric Fever

CXR with infiltrates


5yo girl brought to the pediatric emergency department by her mother due to 3 days of fever.


The patient’s fever was first noted 3 days ago, measured at home to 103°F. It is associated with a moist cough, vomiting, and decreased PO intake. Her mother reports that she appears lethargic and has been urinating less frequently. The patient denies headache, changes in vision, burning with urination, or ear pain. No known sick contacts, attends day care.

PMH (Birth History):

No significant medical/surgical history. Ex-term born NSVD with no complications.


  • VS: 95/65mmHg, 100bpm, 102.6°, 22/min
  • General: Well-appearing, mildly irritated but consolable
  • HEENT: NC/AT, PERRL, oropharynx without erythema, no cervical LAD
  • CV: RRR, no M/G/R
  • Lungs: No evidence of respiratory distress (retractions, flaring), faint crackles over right inferior lung fields
  • Abd: +BS, soft, non-distended, TTP RLQ > LLQ, no rebound/guarding
  • Back: No CVAT


  • CXR PA/Lateral: RML/RLL infiltrate


5yo with 3 days persistent high fever and cough. These symptoms along with examination findings of crackles warranted further imaging (CXR) which revealed infiltrate in the right inferior lung field. The patient appeared clinically stable and was tolerating PO intake in the ED and was discharged home with azithromycin 5mg/kg/dose (with loading dose), clinic follow-up and strict return precautions.

Evaluation and Management of Pediatric Fever

Algorithm for the Evaluation of Pediatric Fever

A System for Pediatric Fever:




  • <3mo: 38.0°C, 100.4°F
  • 3-36mo: 39.0°C, 102.2°F
  • Rectal > oral > axillary

Differential Diagnosis of Pediatric Fever:

Causes Of Fever

Serious Bacterial Illness (SBI):

1) UTI and pyelonephritis

  • Most common cause of SBI
  • Accounts for 3-8% of uncharacterized fevers
  • Female > male, uncircumcised > circumcised
  • Consider BCx, CSF evaluation as 5-10% bacteremic at presentation
  • Urinalysis: LE 75% specificity, Nitrites 97% specificity

2) Pneumonia and sinusitis

  • Sinusitis uncommon <3yo (sinuses unformed)
  • PNA diagnosed with CXR, obtain if findings of respiratory distress (grunting, tachypnea, hypoxemia) or rales on exam

3) Meningitis

  • Diagnose with LP
  • Meningitis suggested if:
    • ANC > 1,000
    • Protein > 80
    • Seizure (particularly complex febrile seizure)

Diagnosis by Age Group:


  • Physical exam findings:
    • Tachypnea, hypoxemia → LRT infection
    • Irritability, inconsolability, bulging anterior fontanelle → meningitis
    • Vomiting/diarrhea → non-specific, GE, AOM, UTI, meningitis
  • History
    • Recent immunization: increased risk of SBI (usually UTI) 24-72h after immunization
    • Confirmed bronchiolitis (viral): enterovirus/parainfluenza associated with SBI


  • Physical exam findings:
    • Viral (URTI, GE) → vomiting, diarrhea, rhinorrhea, cough, rash; still playful and responsive
    • UTI → fever, foul-smelling urine, crying when urinating
    • Meningitis → irritability with handling, vomiting, bulging anterior fontanelle, complex febrile seizures


  • Physical exam findings: presentation more adult-like
  • Watch for:
    • Group A Streptococcal pharyngitis
    • Infectious mononulceosis
    • Kawasaki: high fever (>5d), strawberry tongue, conjunctivitis, desquamating rash on palms/soles

External Links

Acute Pelvic Pain

Pelvic US - free fluidID:

19yo G0, hCG negative, presenting with lower abdominal pain for 3 weeks.


The patient states that she has had progressively worsening lower abdominal pain for the past three weeks. She describes the pain as constant, cramping, currently 8/10 in severity with radiation to the right flank. The pain is improved somewhat with ibuprofen and worsened with movement. She reports subjective F/C, some vaginal bleeding, but no other discharge and no dysuria. She is sexually active with one partner, using condoms occasionally. She has no significant PMH, no history of STI and a PSH of appendectomy. She denies any current or prior T/E/D use.


  • VS: 110/60mmHg, 60bpm, 99.5°, 16/min
  • HEENT: NC/AT, PERRL, EOMI, MMM w/o lesions
  • CV: RRR, no M/G/R
  • Lungs: CTAB
  • Abd: +BS, soft, non-distended, TTP RLQ > LLQ, no rebound/guarding
  • Back: no CVAT
  • Pelvic: external genitalia normal, scant blood in vault, os closed, no discharge, + CMT, + uterine tenderness, + adnexal tenderness


  • TVUS: normal appearing uterus/adnexa, possible free fluid (hemorrhagic vs. inflammatory) in pelvis
  • Wet mount: negative
  • Urine dip: -LE/nitrites, -protein, +blood


19yo G0, hCG negative, with pelvic pain and vaginal bleeding. Findings of lower abdominal tenderness, cervical motion/uterine/adnexal tenderness on examination, and low-grade fever are suggestive of PID. Other considerations include UTI, however, absence of dysuria, CVAT, and negative urine dip do not support this diagnosis. Will evaluate further with GC/CT, and treat empirically with ceftriaxone 250mg IM x1 and doxycycline 100mg PO BID x14d with follow-up in 48h.

Differential Diagnosis of Acute Pelvic Pain:

Common causes:

  • Gynecologic
    • PID, TOA
    • Neoplasm (torsion, rupture)
    • Leiomyoma (torsion, degeneration)
    • Endometriosis
    • Endometritis
    • Ectopic pregnancy
    • SAB
  • Obstetric
    • Labor
    • Uterine rupture
    • Abruptio placentae
    • Diastasis symphesis pubis
  • Non-gynecologic
    • Appendicitis
    • Cystitis (UTI)
    • Diverticulitis
    • Urinary tract calculi
    • Abdominal wall trauma

 Location of pain:



  • discharge + dyspareunia: PID
  • missed menses + cramping/bleeding: SAB, ectopic
  • anorexia, N/V: appendicitis, torsion

A System for the Evaluation and Management of PID:

  • Pathogens: GC, CT, gardnerella, haemophilus
  • Evaluation:
    • Pelvic exam: CMT, uterine tenderness, adnexal tenderness, abnormal discharge, wet mount WBC’s
    • Labs: + GC/CT, ↑ ESR/CRP
    • VS: T > 101°
    • Imaging: thickened tubes, free pelvic fluid, TOA
  • Indications for admission:
    • Acute abdomen, toxic appearance, unstable VS
    • Pregnancy
    • Failed outpatient, can’t tolerate PO
    • TOA
  • Outpatient management:
    • Ceftriaxone 250mg IM x1
    • Doxycycline 100mg PO BID x14d
    • ± Metronidazole 500mg PO BID x14d


  1. Hacker and Moore’s essentials of obstetrics and gynecology. Philadelphia, PA: Saunders/Elsevier, 2010.
  2. CDC – Pelvic Inflammatory Disease – 2010 STD Treatment Guidelines:

3rd Trimester Bleeding


A 34yo G4P2011 at 32w3d by LMP = 2nd trimester ultrasound with a history of GDMA1 is BIB ambulance for vaginal bleeding.


She states that she awoke at 0230 that morning noting significant vaginal bleeding. She denied any associated abdominal pain, uterine contractions, leakage of fluid or other vaginal discharge and has continued to note fetal movement. Her current pregnancy has been uncomplicated though she reports mention of a “low placenta”.


  • VS: 115/80mmHg, 90bpm, 98.1°, 18/min, 99%
  • Gen: Appears distressed
  • HEENT: PERRL, EOMI, MMM, no conjunctival pallor
  • CV: RRR, no M/R/G, Lungs: CTAB
  • Abdomen: gravid (FH 30cm), +BS, NT, no rebound/guarding
  • SSE: os closed, no motion tenderness, several large clots removed from vault


  • NST: baseline 140bpm, moderate variability, accelerations, no decelerations
  • U/S: AFI 10.6, placenta entirely covering internal os

Assessment & Plan:

34yo G4P2011 at 32w3d by L=2 with complete placenta previa confirmed by TVUS presenting with first episode of vaginal bleeding.

Differential Diagnosis of 3rd Trimester Bleeding:


  1. Sakornbut, E., Leeman, L., & Fontaine, P. (2007). Late pregnancy bleeding. American family physician, 75(8), 1199–1206.



A 50 year-old male with a reported two-year history of infrequent spells, presenting with two spells in the past two days.


The patient’s spells began two years ago, he recounts that he was watching television when he lost consciousness and a friend noted he started shaking; he does not recall the event, and awoke in the hospital. The next spell occurred one year later, though the patient is unable to recall much about this episode. The patient remained spell-free until yesterday when he was on a bus, lost consciousness and awoke in a hospital. He notes that he had bit his tongue and lost control of his bladder. He was discharged hours later with a prescription for an AED which he was unable to fill. This morning, the patient had another spell while in the bathroom. His roommate heard him fall, found him on the ground, and noted that his mouth was moving but did not see any other movements.

The patient’s episodes are all associated with loss of consciousness and are followed by 5-10 minutes of disorientation after which he recovers fully. The episodes are sometimes preceded by a feeling of “euphoria”, though this feeling sometimes occurs without subsequent LOC.

The patient denies any associated palpitations, dizziness/LH, chest pain or muscle pain.  He has not had any recent fevers/chills, dysuria, cough, headache, changes in vision, numbness/tingling, weakness, difficulty speaking or swallowing or weight loss. He also denies any history of head trauma.

Physical Examination:

  • VS: Stable and WNL
  • General: Well-appearing, pleasant, and in NAD.
  • HEENT: NC/AT. MMM. Small lesion on tongue.
  • Lungs: CTAB.
  • CV: RRR with occasional ectopic beats, no M/R/G.
  • Abdomen: S/NT/ND. Bowel sounds present.
  • Neurological exam: AAOx4, CN II-XII intact, motor/sensation/reflexes/coordination/gait WNL


  • EKG: Occasional PAC/PVC
  • CT Brain: Unremarkable except for mild age-related cerebral atrophy

Assessment & Plan:

50 year-old male with a history of HTN and a reported two-year history of infrequent spells presenting with two spells in the past two days. The description of the patient’s episodes could be consistent with seizures. Aspects supporting this notion include loss of consciousness and period of confusion following each episode. One of the recent episodes was also associated with tongue-biting and loss of bladder control. Additionally, some episodes are associated with a sensation of euphoria rising from the abdomen to the head which could be indicative of an aura. Characteristics that suggest other causes include the absence of noted convulsions and non-stereotyped nature of each episode which could be due to the patient’s poor recollection of these events and absence of reliable witnesses. In the case of true seizures, the possible etiologies in this patient include a mass, metabolic abnormalities, substance use, or concomitant infection exacerbating an existing propensity for seizure activity. Other, non-seizure causes warranting evaluation include cardiogenic syncope particularly given the evidence of ectopic beats on examination and electrocardiogram.

Differential Diagnosis of Syncope

First, is it syncope? History is very important for distinguishing syncope from other causes (seizure, dizziness, vertigo, presyncope). Ask about precipitating events, prodromal symptoms, post-ictal confusion. Common causes of syncope and their associated symptoms are detailed in the figure below.


  1. Kapoor, W. N. (2000). Syncope. The New England journal of medicine, 343(25), 1856–1862. doi:10.1056/NEJM200012213432507



A 70 year-old female with a PMH of HTN, DM, hyperlipidemia and stage I breast cancer s/p lumpectomy with sentinel LN biopsy several years ago presented for elective surgery complicated by post-operative bleeding. She is now 4 days post-op and was found to be confused, somnolent and occasionally agitated.


The patient could not be interviewed.


  • VS: Stable and within normal limits
  • General: unremarkable except for crackles in bilateral lung bases
  • MSE: only arouses to sternal rub and becomes agitated, moving all four extremities spontaneously and symmetrically.
  • Reflexes: corneal and gag reflexes present, suppresses eye movements with head turn, deep tendon reflexes 3+ throughout UE/LE bilaterally.


70 year-old woman with a history of HTN, DM, hyperlipidemia and breast cancer presents with worsening confusion, somnolence and occasional agitation four days after surgery. The combination of significantly altered consciousness and absence of focal neurological findings, all in the setting of a complicated surgical course suggest delirium.

Differential Diagnosis of Altered Mental Status:

Levels of consciousness

There are different levels of consciousness, they are named in the diagram below but are better described by the characteristics observed.

Initial assessment

Differential Diagnosis for Altered Mental Status


  1. Inouye, S. K. (2006). Delirium in Older Persons. The New England journal of medicine, 354(11), 1157–1165. doi:10.1056/NEJMra052321
  2. Blueprints neurology. Philadelphia: Wolters Kluwer Health/Lippincott William & Wilkins, 2009.
  3. Tindall SC. Level of Consciousness. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 57. Available from:

Headache, vertigo and weakness


30 year-old male with no significant PMH presenting with right-sided “weakness”, vertigo and headache for three days.


The patient was in his normal state of good health until three days prior to admission when he was out shopping and felt a headache and right-sided weakness. The headache came on suddenly, felt “sharp”, 7/10 in severity and radiated from the posterior occiput to his forehead on the right side. The headache was associated with vertigo and nausea/vomiting. At the same time, the patient noticed that he was no longer able to walk, describing “weakness” on the right side. He also began feeling dizzy, describing the sensation as “room spinning”. He denied changes in vision, hearing, difficulty speaking or swallowing (though he has had persistent hiccups for the past few days). He also denied CP, palpitations, SOB. He did seek immediate medical attention at an OSH but is unable to recall what was done and he was discharged from the ER on the same day. He presents 3 days later with persistent symptoms.


  • Mental status: normal
  • CN II-XII: intact with the exception of decreased sensation to sharp touch on right face and decreased gag reflex
  • Motor: normal bulk/tone, strength 5/5 in UE/LE bilaterally
  • Sensory: decreased sensation to pain and temperature on left body
  • Gait: wide-based, unable to tandem, heel, toe walk. Walking in place, he turns to the right.


30 year-old male with no PMH presenting with 3 days of HA, vertigo, hiccups, right-sided ataxia, and alternating decreased pain and temperature sensation on ipsilateral face and contralateral hemibody. These symptoms are suggestive of a brainstem lesion, localizing to the medulla. Hiccups suggest involvement of nucleus ambiguus (CN IX, X, XII). Alternating decreased pain/temperature sensation suggests involvement of the spinal tract of CN V, and interruption of fibers of the descending spinothalamic tract. These findings point further to a lesion in the right lateral medulla, likely vascular given the rapid onset of symptoms. Associated findings of right-sided ataxia suggests involvement of the superior cerebellar peduncle (restiform body) in the posterior lateral medulla. An MRI brain showed the lesion shown in Fig-1, and a CTA head/neck the following day showed dissection of the right vertebral artery.

A System for Cerebrovascular Disease:

Types of strokes

Clinical characteristics of strokes

Strokes are characterized by the sudden onset of focal neurological deficits. These are typically unilateral and consciousness is generally maintained.

  • dysphasia
  • dysarthria
  • weakness
  • ataxia
  • sensory loss
  • neglect
  • hemianopsia

If some of these typical features are not present (ex. gradual onset, significantly impaired consciousness, seizures early), consider alternative diagnoses (ex. hypoglycemia, subdural hematoma, mass, postictal paresis, migraine).

Common causes of stroke

The most common causes are atherosclerosis (leading to thromboembolism or local occlusion) and cardioembolism. If the patient does not have risk factors, consider alternatives:

  • contralateral ptosis/miosis: carotid artery dissection affecting sympathetic fibers
  • fever + murmur: infective endocarditis
  • HA + ↑ESR: giant-cell arteritis


  1. Agabegi, S. (2013). Step-up to medicine. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins.
  2. van der Worp, H. B., & van Gijn, J. (2007). Acute Ischemic Stroke. The New England journal of medicine, 357(6), 572–579. doi:10.1056/NEJMcp072057

Intro to ddxof

I’m a medical student currently rotating through clinical clerkships resident assistant professor in emergency medicine. The purpose of this website is to force me to learn. Recently, I’ve found it increasingly difficult to study from review books, and even more difficult to recall and apply that information practically. What has been working is reading heavily about specific cases I’ve seen. Having a real person in mind, hearing their complaints, doing their examination and then supplementing the experience with targeted reading sticks far better.

As for the format, something that has been hammered into me over the past year is to be systematic in everything I do. The benefits being that I’m less likely to miss stuff if I approach everything the same way. The other benefit for me is that I find these systems to be a better way to learn. Less mnemonics, more flowcharts.

So, I’ll select appropriate cases I encounter (altering identifying information of course), read into it a bit, and create a systematic approach for the evaluation, diagnosis and management of that chief complaint.

The site’s going to be a bit rough, the goal is to make it easy to quickly archive these experiences for future reference and learning.