What Is the Cause of This Rash?

Author:
David L. Kaplan, MD—Series Editor

Citation:
Kaplan DL. What is the cause of this rash? Consultant. 2017;57(6):352,354.

This 16-year-old girl presented with a 1-month history of a slightly itchy rash on the extremities and trunk. The rash had appeared after an upper respiratory infection that had resolved uneventfully. She was otherwise healthy.

Answer on next page

Answer: Guttate Psoriasis

Because the sparse lesions made the clinical diagnosis less certain, a biopsy was taken, the results of which confirmed the diagnosis of psoriasis.

Guttate psoriasis is characterized by the acute onset of small (1-10 mm in diameter), droplike, erythematous to salmon-pink papules, usually with a fine scale. This variant of psoriasis primarily occurs on the trunk and the proximal extremities, but it may have a generalized distribution. New guttate psoriasis lesions continue to develop during the first month of the disease; they remain stable during the second month, and then start to fade during the third month. Typically, guttate psoriasis occurs after a streptococcal infection and occurs more commonly in persons younger than 30 years.

David L. Kaplan, MD, is a clinical assistant professor of dermatology at the University of Missouri–Kansas City School of Medicine in Kansas City, Missouri, and at the University of Kansas School of Medicine in Kansas City, Kansas. He practices adult and pediatric dermatology in Overland Park, Kansas.