Cutaneous Infectious Diseases Flashcards

Burrows in the finger web spaces with intense nocturnal pruritus are characteristic of infestation by:

Answer: Sarcoptes scabiei

Scabies is caused by Sarcoptes scabiei, which burrows in the skin and produces intense itching worse at night.

First-line topical treatment for classic scabies is:

Answer: Permethrin 5% cream

Permethrin 5% cream is the first-line scabicide, applied to the entire body from the neck down.

Crusted (Norwegian) scabies is most likely to develop in which population?

Answer: Immunocompromised or institutionalized patients

Crusted scabies, with massive mite burden and thick hyperkeratotic crusts, occurs in immunocompromised or debilitated patients.

A painless, indurated genital ulcer (chancre) with regional lymphadenopathy is the primary lesion of:

Answer: Syphilis

The painless chancre of primary syphilis is caused by Treponema pallidum and heals spontaneously.

Copper-colored papulosquamous lesions involving the palms and soles are characteristic of:

Answer: Secondary syphilis

Secondary syphilis classically produces a papulosquamous eruption including the palms and soles.

An expanding erythematous annular rash with central clearing (erythema migrans) after a tick bite indicates:

Answer: Lyme disease

Erythema migrans, caused by Borrelia burgdorferi following an Ixodes tick bite, is the hallmark of early Lyme disease.

Which infestation is diagnosed by identifying nits firmly attached to hair shafts?

Answer: Pediculosis capitis

Head lice (Pediculosis capitis) are diagnosed by finding viable nits cemented to the hair shafts.