MCQ – 99606

Correct Answer � A Explanation

• Primary skin lesions refer to initial, characteristic dermatologic findings that are directly caused by the disease, not secondary effects or nonspecific rashes.

• These include macules, papules, vesicles, pustules, nodules, etc., that are part of the typical presentation.

Leptospirosis 

• Leptospirosis is a spirochetal infection caused by Leptospira interrogans.

• It is not typically associated with any characteristic primary skin lesions.

• Cutaneous findings (if present) are non-specific, like conjunctival suffusion, petechiae, or purpura in severe cases (Weil’s disease), but these are secondary features, not primary lesions.

Why the Other Options Are Incorrect :

B. SLE (Systemic Lupus Erythematosus) 

• Classic butterfly (malar) rash, discoid lesions, photosensitive rashes are primary cutaneous features.

• Skin involvement is a major diagnostic criterion of SLE.

C. Hepatitis B 

• Can be associated with:

  • Urticarial rash

  • Maculopapular rash

  • Polyarteritis nodosa (PAN) – associated with palpable purpura

• These are direct immunologic manifestations of the viral infection.

D. Infectious mononucleosis 

• Caused by Epstein-Barr virus (EBV).

• May cause maculopapular or morbilliform rash, especially after amoxicillin administration.

• Rashes may occur even without drugs, due to immune response to the virus.