The Ultimate OSCE Spot Diagnosis Checklist for Medical Students

Top 10 Spot Diagnosis Cases for OSCE Success
Spot Diagnosis is one of the most crucial components of Objective Structured Clinical Examinations (OSCEs). Examiners are not only testing your ability to recall knowledge but also your clinical acumen, pattern recognition, and ability to translate theoretical learning into immediate bedside diagnosis. Mastering spot diagnoses requires visual familiarity, structured thinking, and quick recall of key clinical signs. Below are the Top 10 Spot Diagnosis Cases that every medical student and junior doctor should know, updated to reflect common OSCE practices in 2025.

1. Clubbing of Fingers (Digital Clubbing)
Why It Appears in OSCEs
Clubbing is a high-yield OSCE favorite because it is simple to show, easy to test, and linked to a wide range of systemic diseases.

Key Diagnostic Features

• Bulbous enlargement of distal phalanges.
  
  
• Loss of the normal angle between nail bed and nail fold (Lovibond’s angle >180°).
  
  
• Increased sponginess of nail bed.
  
  
• “Drumstick” appearance in severe cases.
  

Associated Conditions

• Pulmonary: Lung cancer, bronchiectasis, interstitial lung disease.
  
  
• Cardiac: Cyanotic congenital heart disease, infective endocarditis.
  
  
• Gastrointestinal: Cirrhosis, inflammatory bowel disease.
  

Exam Tip: Always perform the “Schamroth window test” and state one respiratory, one cardiac, and one GI cause.


2. Facial Palsy
Why It Appears
A classic OSCE scenario because it tests neuroanatomy, cranial nerve examination, and differential diagnosis.

Key Diagnostic Features

• Unilateral facial asymmetry.
  
  
• Inability to raise eyebrow or close eyelid tightly (lower motor neuron lesion).
  
  
• Sparing of the forehead in upper motor neuron lesion (due to bilateral innervation).
  

Common Causes

• LMN: Bell’s palsy, Ramsay Hunt syndrome, parotid tumor.
  
  
• UMN: Stroke, multiple sclerosis.
  

Exam Tip: Always state whether forehead involvement is present to distinguish LMN vs UMN lesions.

3. Jaundice (Icterus)
Why It Appears
Easily demonstrated on patients or photos; integrates clinical medicine with biochemistry.

Key Diagnostic Features

• Yellow discoloration of the sclera (best observed under natural light).
  
  
• Possible generalized skin yellowing.
  
  
• Dark urine and pale stools are seen in obstructive jaundice.
  

Underlying Causes

• Pre-hepatic: Hemolysis.
  
  
• Hepatic: Viral hepatitis, cirrhosis, alcoholic liver disease.
  
  
• Post-hepatic: Gallstones, pancreatic carcinoma, cholangiocarcinoma.
  

Exam Tip: Describe where you first noticed jaundice (sclera), then categorize it into pre-hepatic, hepatic, or post-hepatic causes.

4. Skin Rash Patterns
Why It Appears
Dermatology spot diagnoses are visual, memorable, and can test systemic associations.

Examples

• Malar rash (butterfly rash): systemic lupus erythematosus (SLE).
  
  
• Target lesions: Erythema multiforme.
  
  
• Psoriatic plaques: Silvery scaling on extensor surfaces.
  
  
• Vesicular rash in dermatomal distribution: Herpes zoster.
  

Exam Tip: Use the “SALT” framework when describing: Site, Arrangement, Lesion type, and Topography.

5. Goiter and Thyroid Swelling
Why It Appears
Palpable neck swellings are exam staples that test both endocrinology and surgical approaches.

Key Diagnostic Features

• Diffuse goiter (Graves’ disease).
  
  
• Nodular goiter (multinodular or solitary toxic nodule).
  
  
• Retrosternal extension signs (tracheal deviation, venous congestion).
  

Associated Symptoms

• Hyperthyroidism: Weight loss, tremor, tachycardia.
  
  
• Hypothyroidism: Fatigue, dry skin, bradycardia.
  

Exam Tip: Always mention movement with deglutition (thyroid swellings move) and ask about compressive symptoms.

6. Splenomegaly
Why It Appears
It integrates systemic pathology (hematology, infections, portal hypertension) with examination skills.

Key Diagnostic Features

• Enlarged, firm mass arising from the left hypochondrium.
  
  
• Moves inferomedially with respiration.
  
  
• Notched edge palpable.
  

Common Causes

• Hematology: Chronic myeloid leukemia, lymphoma, hemolytic anemia.
  
  
• Infective: Malaria, kala-azar.
  
  
• Portal hypertension: Cirrhosis.
  

Exam Tip: Always palpate from the right iliac fossa towards the left hypochondrium.

7. Parkinsonian Facies and Tremor
Why It Appears
Neurological signs are fundamental in OSCE testing.

Key Diagnostic Features

• Mask-like facies with reduced blinking.
  
  
• Pill-rolling tremor (resting tremor, disappears with movement).
  
  
• Rigidity and bradykinesia.
  
  
• Shuffling gait.
  

Exam Tip: Demonstrate tremor assessment by asking the patient to rest their hands on their lap, then distract them to make the tremor more visible.

8. Koilonychia (Spoon-shaped Nails)
Why It Appears
Simple, visual, and integrates systemic medicine with hematology.

Key Diagnostic Features

• Thin, brittle nails with concavity.
  
  
• May hold a drop of water in the concavity.
  

Associated Conditions

• Iron deficiency anemia.
  
  
• Rarely: Hemochromatosis, Plummer–Vinson syndrome.
  

Exam Tip: Always link the finding with systemic signs like pallor, glossitis, or angular cheilitis.

9. Corneal Arcus and Kayser-Fleischer Ring
Why It Appears
Ophthalmological findings highlight systemic disorders and metabolic diseases.

Corneal Arcus

• Grey-white ring at the corneal periphery.
  
  
• Seen in hyperlipidemia (especially in young patients).
  

Kayser-Fleischer Ring

• Golden-brown ring at the corneal margin.
  
  
• Seen in Wilson’s disease (copper deposition).
  

Exam Tip: Always mention that the diagnosis is confirmed by slit lamp examination.

10. Varicose Veins of the Lower Limb
Why It Appears
Surgical OSCE stations frequently involve examination of varicose veins.

Key Diagnostic Features

• Dilated, tortuous veins are visible on standing.
  
  
• Skin changes: Hyperpigmentation, eczema, lipodermatosclerosis, ulcers (especially gaiter area).
  
  
• Positive Trendelenburg or Perthes test (in exam setup).
  

Underlying Causes

• Primary valvular incompetence.
  
  
• Secondary to DVT.
  

Exam Tip: Always examine standing, inspect from groin to ankle, and mention complications.

Final Exam Strategy
Mastering these 10-spot diagnoses ensures you are prepared for a broad range of OSCE cases. Each case tests a combination of observation, description, underlying pathology recall, and ability to connect signs with systemic disease. To succeed:

• Practice repeatedly with images and real patients.
  
  
• Learn a structured approach to description.
  
  
• Link each finding to at least 2–3 systemic associations.