Persistent contact dermatitis

Abstract

A 46-year-old man presented with a 6- to 7-year history of an eczemataus eruption on the dorsal aspect of the feet (figure 1). The patient had been wearing leather oxford shoes to work for 18 years. He had used several corticosteroid creams on the feet, but improvement was limited.

A potassium hydroxide (KOH) test was negative for fungal infection. Two-day patch tests using a screening tray of 24 common allergens as well as small samples from four pairs of the patient's shoes were also negative. Further treatment with topical and systemic corticosteroids and antibiotics provided only short-term relief.

One year following the initial visit, 4-day patch tests using a vehicle tray, the patient's medications, and samples from his work shoes revealed strong positive reactions to amcinonide cream and the shoes. The ingredients list of the amcinonide cream was obtained from the manufacturer, and subsequent patch tests revealed positive reactions to both the active ingredient (amcinonide) and the emulsifying wax (figure 2). The rash cleared when the amcinonide cream was discontinued and replaced with a corticosteroid from another class.

We concluded that a reaction to the leather material in the patient's work shoe was complicated by a reaction to amcinonide cream. We believe that both the active ingredient and the emulsifying wax were relevant factors in the persistence of allergic dermatitis.