Patterns of cosmetic contact allergy.

Certain patterns of dermatitis, such as those affecting the face, eyelids, lips, and neck, should raise the suspicion of a cosmetic-related contact allergy. Patch testing with a broad screening series, supplemented by a patient's own personal care products, should be considered when evaluating patients with suspected cosmetic dermatitis. Once the offending allergen is identified, an avoidance regimen should be established to avoid further exposure.