The many faces of nickel allergy.

Hypersensitivity reactions to nickel are one of the most common in the modern world. Nickel allergy prevalence is constantly growing in many countries and represents a major health and socioeconomic issue. Herein the current understanding on nickel allergy is summarized with a practical approach to the dermatologist, allergist, and general practitioner. The personal experience with some practical clinical cases of nickel dermatitis is shared. A special emphasis is put on the possible strategies for treatment and prevention of the disease.