Derm Chat Flashcards
A 6-year-old boy presents with crusty, honey-coloured lesions around his nose and mouth. What is the most likely diagnosis?
A. Eczema herpeticum
B. Impetigo
C. Molluscum contagiosum
D. Herpes simplex
E. Folliculitis
B. Impetigo
Explanation: This classic presentation of golden crusts in a child is typical of impetigo, a contagious superficial bacterial infection.
A 28-year-old patient reports intense itching, especially at night. Examination reveals burrows between the fingers. What is the most likely diagnosis?
A. Tinea manuum
B. Psoriasis
C. Contact dermatitis
D. Scabies
E. Lichen planus
D. Scabies
Explanation: Scabies presents with severe itching and visible burrows, often in the web spaces of the hands, and worsens at night.
Which of the following is the first-line treatment for tinea corporis (ringworm) in a healthy adult?
A. Oral fluconazole
B. Topical clotrimazole
C. Oral terbinafine
D. Topical terbinafine
E. Oral ketoconazole
D. Topical terbinafine
Explanation: Topical terbinafine is the first-line treatment for localized tinea corporis due to its fungicidal action.
A 35-year-old woman presents with circular patches of hair loss. The affected areas are smooth and non-scaly. What is the most likely diagnosis?
A. Telogen effluvium
B. Alopecia areata
C. Tinea capitis
D. Trichotillomania
E. Androgenetic alopecia
B. Alopecia areata
Explanation: Smooth, round, non-scarring hair loss patches suggest autoimmune alopecia areata.
A patient presents with yellow, thickened toenails and subungual debris. What is the most appropriate initial investigation?
A. Potassium hydroxide prep
B. Nail biopsy
C. Fungal culture of skin scrapings
D. Nail clippings for microscopy and culture
E. Nail punch
D. Nail clippings for microscopy and culture
Explanation: Confirming fungal nail infection before treatment requires microscopy and culture of nail clippings.
