Cosmetics and contact dermatitis.

A complete work-up of most patients with cosmetic allergies can be performed satisfactorily in a dermatologist's office without expensive equipment. After taking a complete history and performing a thorough examination, a biopsy is seldom required. Examine all the patient's cosmetics, eliminate the strong irritants, and proceed with product patch testing. Patch testing with the AAD allergen test tray at the same time is frequently helpful. When results are doubtful or do not fit with the information obtained from the history and examination, supplemental provocative use tests often clarify what information is clinically relevant. Patch testing with ingredients that dermatologists have obtained from cosmetic manufacturers or other sources often provides a helpful, definitive answer for the patient. Always provide the patient with information about cross-reactions and the official name of the allergen as it will appear on a cosmetic label to prevent recurrences.