What Explains This Recurrent Rash?

Author:
David L. Kaplan, MD—Series Editor

Citation:
Kaplan DL. What explains this recurrent rash? Consultant. 2017;57(8):477-478.

This 51-year-old woman presented with a 2-year history of chronic hand eczema that would partially respond to topical corticosteroids, only to recur. She denied any new exposure history. She had not had the condition in the past.

Answer on next page

Answer: Psoriasis

The patient had psoriasis, which originally had been diagnosed and treated as eczema.

All of the approaches listed above—patch testing, KOH prep testing, and examination of the fingernails, elbows, knees, and feet—are important maneuvers in making the correct diagnosis of psoriasis. The fingernails will show possible signs of psoriasis or lichen planus. Tinea pedis of the feet could result in dyshidrosis and yield KOH prep test results that are positive for fungal infection.

On closer physical examination, this patient also had involvement of her elbows, which allowed the diagnosis of psoriasis to be made. The well-demarcated lesions on the palms support the diagnosis. Nevertheless, it is important to remember that patients can have overlapping diagnoses.

While topical treatment is the safest option for psoriasis, patients with extensive involvement often require systemic therapy. This is especially true for difficult-to-treat areas such as the hands. This patient was started on topical corticosteroids alternating with calcipotriene.

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.