photoallergic contact dermatitis

Pathology

• results when sunlight acts on an ingredient in a topical agent & the patient is allergic to the sunlight-changed chemical
• neither exposure to sunlight alone or exposure to the topical agent alone causes a problem, but when the patient applies the topical agent & goes out into the sunlight, eczema develops

Diagnostic procedures

• photopatch testing

More general terms

• contact dermatitis (exogenous eczema)