Dermatology Flashcards

A 17-year-old male presents with mild acne vulgaris consisting primarily of comedones with few papules. Which topical agent is considered first-line monotherapy?

Answer: Topical tretinoin (retinoid)

Topical retinoids are first-line for comedonal acne because they normalize follicular keratinization and prevent microcomedo formation.

A 35-year-old presents with well-demarcated, erythematous plaques with silvery scales on the elbows and knees. The most likely diagnosis is:

Answer: Psoriasis vulgaris

Psoriasis vulgaris classically presents with well-demarcated erythematous plaques covered with silvery-white scales on extensor surfaces such as elbows and knees.

A 2-year-old presents with pruritic, erythematous, weeping patches on the cheeks and extensor surfaces. Family history is positive for asthma and hay fever. The most likely diagnosis is:

Answer: Atopic dermatitis

Atopic dermatitis presents in infants on the cheeks and extensor surfaces with a personal or family history of atopy (asthma, allergic rhinitis, eczema) — the atopic triad.

Which feature of a pigmented skin lesion is MOST concerning for malignant melanoma?

Answer: Irregular border with multiple colors (tan, brown, black)

Irregular borders and multiple colors are hallmark ABCDE criteria for melanoma, reflecting uncontrolled, asymmetric tumor cell proliferation.

A patient develops a pruritic, erythematous vesicular rash on the wrists after wearing a new metal watch. The most likely diagnosis is:

Answer: Allergic contact dermatitis

Allergic contact dermatitis from nickel (common in metal watches) is a Type IV hypersensitivity reaction presenting with pruritic vesicular rash confined to the contact area.

A 22-year-old presents with scaling, pruritic patches in the groin. KOH preparation reveals hyphae. The most appropriate treatment is:

Answer: Topical antifungal such as clotrimazole

Tinea cruris is a dermatophyte infection confirmed by KOH prep showing hyphae; topical antifungals such as clotrimazole are first-line treatment.

A 45-year-old woman presents with persistent facial erythema, flushing, and papulopustules on the cheeks and nose. She reports triggers including alcohol and spicy foods. The most likely diagnosis is:

Answer: Rosacea

Rosacea presents with centrofacial erythema, flushing, and papulopustules without comedones, commonly triggered by alcohol, spicy foods, heat, and sun exposure.