StethopediaClinical Skills Guide
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Appendices

Appendix 3Differential Diagnoses Practice

  • MF1–4, Integration MF
  • PDF pp. 486–487
On this page
  • NOTE: In the MF1 clinical skills student guide in the section on Associated Symptoms, it was said that a Differential Diagnosis list takes time and practice to grow, as you continue to read around new diseases. Through MF1-4, you will be exposed to a variety of tutorial cases, clinical encounters, etc. to begin to put a DDx together for common chief complaints. Lists presented are by no means exhaustive.
  • This is in addition to the VINDICATE general strategy for running through possible Differential Diagnoses.

What Are Some High Yield Head-To-Toe Common Etiologies to Keep in Mind for OSCE?

CC: Top 5-6 Etiologies (With System)

Dyspnea

  • Cardiac: Cardiomyopathy (Restrictive, Hypertrophic, Dilated); Arrhythmias; ACS (MI, unstable angina); Angina
  • Respiratory: Airway Obstruction (Anaphylaxis, COPD, Asthma, Bronchiectasis, Foreign body aspiration); Parenchymal (Pneumonia, Interstitial Lung Disease); Large Vessel Disease (Vasculitis, Emboli e.g. Septic endocarditis); Small Vessel Disease (Pulmonary Embolism, Pulmonary HTN); Extrapulmonary (Pleural Effusions – 2° malignancies, CHF, Infectious; Rib Fracture; Neuromuscular – GBS, Myasthenia Gravis, Lambert Eaton Syndrome; Kyphosis/Scoliosis)

Cough

  • Acute: Respiratory Tract Infection; Foreign Body Aspiration
  • Chronic Productive: Pneumonia + COPD; PE; Lung Cancer
  • Chronic Non-Productive: Asthma; Post-Nasal Drip; GERD; ACEi S/E (non-productive)

Palpitation

  • Cardiac Arrhythmia: Atrial Fibrillation; Atrial Flutter; Premature Atrial Contractions; Atrial Tachycardia; Multifocal Atrial Tachycardia; AV Node Re-Entry Tachycardia; AV Re-Entry Tachycardia; Premature Ventricular Contractions; Ventricular Tachycardia; Ventricular Fibrillation
  • Sinus Tachycardia: Anxiety/Emotional Stress/Panic Disorder; Hyperthyroidism; Fever; Hypovolemia; Stimulants (Caffeine, Nicotine, Alcohol); Medications; Blood Loss; Pheochromocytoma; Hypoglycemia; Idiopathic
  • Normal Sinus Rhythm: Heightened cardiac perception

Chest Pain

  • Cardiac: MI; Angina; Tamponade/Pericarditis; Aortic Dissections
  • Respiratory: Pulmonary Embolism; Pneumonia; Pneumothorax
  • GI: GERD/Esophageal Spasm; Pancreatitis; Peptic Ulcer Disease (PUD); Esophageal Rupture/Mallory-Weiss Tear
  • MSK/Misc.: Costochondritis; Rib Fracture (#); Anxiety/Panic Attack; Herpes Zoster (Shingles)

HTN

  • Essential (90%) – LVH, Atherosclerosis
  • Secondary (10%) – Renal Artery stenosis, PCKD, Thyroid, Cushing’s, Aortic Dissection/Coarctation

Syncope

  • Etiology: A sudden decrease in, or brief cessation of, cerebral blood flow
  • Cardiac Causes – Impaired Cardiac Output:
    • Obstructive: Valvular disease, Hypertrophic Cardiomyopathy, PE, Pulmonary HTN, Cardiac Tamponade
    • Arrhythmias: Bradyarrhythmias (e.g. AV Nodal block); Tachyarrhythmias (both Atrial and Ventricular)
    • Ischemia
  • Non-Cardiac Causes:
    • Neurocardiogenic: Vasovagal (increasing vagal tone transiently slows heart rate)
    • Orthostasis: Drugs, Volume contraction, Autonomic Dysfunction E.g. Diabetic autonomic neuropathy
    • Central Nervous System: Stroke, TIA (uncommon causes)
    • Metabolic: Hypoglycemia, hyponatremia

Fatigue

  • Cardiac: CHF; Atrial Fibrillation; MI
  • Resp: COPD; Obstructive Sleep Apnea
  • Heme: Iron deficiency anemia; Chronic Myeloid Leukemia; Non-Hodgkin’s Lymphoma; Hodgkins Lymphoma
  • GI: Celiac disease
  • Endocrine: Diabetes Mellitus (DKA, Hypoglycemia, Hyperglycemia), Hypothyroidism, Hyperthyroidism Addison’s Disease
  • Infectious: EBV Infection (mononucleosis); Influenza Infection; HIV Infection; Toxoplasmosis; Lyme Disease; TB
  • Medications: Antihistamines; Anti-hypertensives; Anti-arrhythmics, Anti-depressants, Anti-epileptics, Anti-emetics, Corticosteroids, Diuretics, Anti-psychotics
  • Neuro: Stroke; Parkinson’s Disease; MS
  • Psychiatric: Alcohol dependence; drug dependence (esp. nicotine, caffeine, Marijuana, Cocaine, Heroin); Depression; Insomnia

Dysphagia

  • In the Lumen: Food bolus; foreign body
  • In the Wall: GERD
  • Outside the Wall: Goitre; Paraesophageal hiatal hernia (rolling); Mediastinal tumors
  • Neuromuscular: Cerebrovascular Accident (CVA); Guillain-Barre Syndrome (GBS)

Abdominal Pain

  • Important to rule out: Cardiac causes re. Ask if chest pain present on Assoc. Sx.
  • Upper Abdomen: GERD; Peptic Ulcer Disease (Pain 1-3 hrs post-prandial); GU (Anorexia, Food Aversion)
  • Midline Abdomen: Abdominal Aortic Aneurysm (AAA)
  • Poorly Localized: Small Bowel Obstruction (SBO) & Large Bowel Obstruction (LBO)
  • RUQ Pain: Liver and Gallbladder → Biliary Colic (colicky pain), Cholecystitis, Choledocolithiasis, ascending cholangitis (infected stone), Hepatitis
  • LUQ Pain: Spleen and Pancreas → Pancreatitis (pain radiates to back re dermatome), Splenitis
  • RLQ Pain: Appendicitis (begins poorly localized at umbilicus unless retrocecal appendix orientation)
  • LLQ Pain: Diverticulitis (Diarrhea, Fever)
  • Also on DDx: Inflammatory Bowel Disease (IBD); Volvulus; Hernia; Perforated bowel; Mesenteric ischemia; Toxic Megacolon (re C. Difficile infection); testicular torsion, ovarian torsion, prostatitis, ectopic pregnancy

Vomiting & Diarrhea

GASTROENTERITIS, TTP HUS (anemic, fever, thrombosis, AKI), Appendicitis, Cystic Fibrosis, Food Allergies, IBS, IBD, Hypothyroidism, UTIs, Infectious (C. Diff)

Flank Pain

Pyelonephritis, Pancreatitis, Renal Calculi, Bowel Obstruction, AAA, Gastric Ulcer, Bowel Perforation, Biliary Colic

Hematuria

Urethritis, Epididymitis, Acute Prostatitis, Cystitis, Pyelonephritis, Glomerulonephritis, Cancer

AKI

Prerenal (CHF, AAA/Dissection, Hepato-renal syndrome, Dehydration), Renal (ATN – Toxic or Ischemic, AIN – Allergy-mediated, or AGN – SLE, Nephritic/Nephrotic), and Post-Renal (Obstructive-BPH, Fibrosis, Gynecological cancer)

Fever

  • Cause 1: INFECTIOUS – Ask about Sick Contacts
    • Resp → Hx: Cough, SOB, Runny Nose; GI → Hx: NVD, Abdo Pain; GU → Hx: FUND; Derm → Hx: Cuts, rashes
  • Cause 2: Malignancy - Ask Constitutional Symptoms
  • Cause 3: Inflammatory – Ask About Joint Pain (Including Autoimmune)
  • Cause 4: Drug Reaction

Upper GI Bleed (UGIB)

  • Esophageal Varices (dilated submucosal veins distal 1/3rd of Esophagus, often from Portal Hypertension as one of the natural shunts along with Rectal Varices, Umbilical re Caput Medusae and Pericolic Gutters)
  • Esophageal Tears: Mallory-Weiss Tear (partial thickness tear); vs. Boerhaave Syndrome (full thickness tear)
  • Peptic Ulcer Disease: Occurs both in Stomach (H. Pylori 50% cases) & Duodenum (H. Pylori 90+% cases); NSAIDS
  • Arteriovenous Malformations (AVMs)
  • Gastric Cancer
  • Gastritis: Stress, Inflammatory
  • Esophagitis
  • Massive Epistaxis (may present similarly)
  • Crohn’s

Lower GI Bleed (LGIB)

  • Cancers & Adenomatous Polyps
  • IBD: Crohn’s and Ulcerative Colitis
  • Diverticular Bleed
  • Ischemic Colitis
  • Hemorrhoids
  • Angiodysplasia: Small AVMs in bowel, a distortion of vascular structures with advancing age
  • Infectious: Mnemonic – Your Stool Smells Extremely Crappy (Yersinia, Shigella, Salmonella, E. Coli O157:H57, C. Difficile); Viruses; Parasites
  • Lymphoma
  • Trauma: Including Foreign Body

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