Q1. A cardinal sign of leprosy is: A. An itchy scaly patch B. A skin patch with DEFINITE LOSS OF SENSATION C. A blistering rash D. Symmetrical flexural eczema ANSWER: B. Why: the cardinal signs are a patch with definite sensory loss, thickened peripheral nerves, and a positive skin smear. Patients rarely report numbness because they have not noticed it. LEARNING POINT: test sensation in EVERY hypopigmented patch.

Q2. Psoriasis characteristically affects: A. The FLEXURES with ill-defined itchy patches B. EXTENSOR surfaces with well-demarcated silvery-scaled plaques C. Only the palms D. The finger web spaces at night ANSWER: B. Why: psoriasis favours extensor surfaces, scalp and nails. Eczema favours flexures and is ill-defined; web-space itch at night suggests scabies. LEARNING POINT: distribution usually separates the three.

Q3. A woman treated twice for scabies still itches, and her whole family is scratching. The likely reason is: A. Resistance to treatment B. UNTREATED HOUSEHOLD CONTACTS causing reinfection C. The diagnosis is wrong D. She needs oral antibiotics ANSWER: B. Why: scabies clusters in households through prolonged close contact. Treating one person while contacts remain untreated guarantees reinfection. LEARNING POINT: treat all contacts simultaneously, and warn that itch may persist for weeks after cure.

Q4. A patient develops a widespread rash ten days after starting a new drug, with mouth ulcers, red eyes, blistering and fever. The immediate action is: A. Antihistamine and continue the drug B. STOP THE DRUG IMMEDIATELY and obtain specialist help C. Topical steroid only D. Reassure — drug rashes are self-limiting ANSWER: B. Why: mucosal involvement with blistering and systemic illness marks a severe cutaneous drug reaction carrying significant mortality. Continuing the drug worsens it. LEARNING POINT: mucosal involvement is the red flag that separates a trivial drug rash from an emergency.

Q5. A diabetic man treated for cellulitis has pain far more severe than the visible redness suggests, systemic toxicity and dusky skin. This suggests: A. Simple cellulitis needing longer antibiotics B. NECROTISING soft tissue infection — surgical emergency C. Deep vein thrombosis D. Contact dermatitis ANSWER: B. Why: necrotising infection tracks along the fascial plane beneath the skin, so the surface may look unimpressive while the patient is severely unwell. LEARNING POINT: pain out of proportion is the single most useful early clue.

Q6. Why does leprosy cause deformity? A. The organism directly destroys bone B. NERVE DAMAGE causes anaesthesia, so injuries go unnoticed and become infected C. It is caused by malnutrition D. Treatment causes it ANSWER: B. Why: anaesthetic hands and feet are repeatedly injured without the patient noticing, leading to ulceration, infection and tissue loss. Early treatment prevents the nerve damage. LEARNING POINT: the disability is preventable, which is why early diagnosis matters so much.

Q7. Which feature distinguishes herpes zoster from other vesicular rashes? A. It is itchy rather than painful B. Vesicles confined to a SINGLE DERMATOME, not crossing the midline C. It affects only the face D. It never causes pain ANSWER: B. Why: zoster reflects reactivation in a single sensory ganglion, so the rash respects the dermatome and the midline. Pain often precedes the rash by several days. LEARNING POINT: a clean anatomical discriminator worth remembering.