Patients with chronic hand dermatitis should be patch tested. This can be performed a dermatologist or allergist. Teaching centers usually have a contact dermatitis expert on the staff of the dermatology Department. These physicians have the testing material and experience to evaluate very complicated cases. Perform a potassium hydroxide examination on a skin scraping if a fungal infection is suspected.

Patch test allergens. Chemicals that commonly cause allergic contact dermatitis are incorporated into a standard patch testing screening kit.