Bacterial, Viral & Fungal Infections MCQs

Dermatology · 6 free questions with answers & explanations.

1. A 6-year-old child presents with honey-coloured crusted lesions around the nose and mouth that started as vesicles 3 days ago. Gram staining of the exudate shows Gram-positive cocci in chains. Culture confirms the causative organism. Which organism and complication should the treating physician be most vigilant about?
2. A 35-year-old construction worker presents with painful grouped vesicles on an erythematous base along the right T4 dermatome. He reports severe burning pain that preceded the rash by 3 days. Two weeks later he develops persistent shooting pain in the same distribution despite the rash resolving. What is the mechanism of this persistent pain?
3. A 24-year-old sexually active woman presents with multiple soft, non-tender, flesh-coloured papules with a central dell on her lower abdomen and pubic area. The lesions have a characteristic cheesy white core when expressed. Histopathology of one lesion would show which of the following?
4. A 19-year-old woman presents with intense nocturnal pruritus affecting her interdigital spaces, wrists, and axillary folds. Her college roommate has similar complaints. On dermoscopy, a triangular structure resembling a 'hang-glider' or 'delta wing' is seen at the end of a burrow. What is the causative agent and the drug of choice?
5. A 30-year-old farmer presents with a well-defined, hypopigmented patch on his trunk with broken hair follicles and fine scaling. Wood's lamp examination reveals bright yellow-green fluorescence. KOH mount shows short curved hyphae and clusters of round spores resembling 'spaghetti and meatballs.' What is the diagnosis and the recommended systemic treatment?
6. A 55-year-old diabetic man presents with a painful, rapidly enlarging carbuncle on the back of his neck. Central fluctuance is present with multiple interconnected follicular openings draining pus. Gram stain shows Gram-positive cocci in clusters. Beyond incision and drainage, which systemic antibiotic would be MOST appropriate considering the current resistance pattern in India?