Nickel allergy: localized, id, and systemic manifestations in children.

Nickel is the most common allergen causing allergic contact dermatitis in patch-tested children, especially in female children. Allergy to this metal can manifest in a variety of ways. In this case series, we present four children to illustrate the different presentations of nickel allergy confirmed by patch testing. Localized, id, and systemic nickel reactions are reviewed, as well as the diagnosis and management of nickel allergic contact dermatitis. While localized dermatitis in areas of direct contact to the allergen is the most common and easiest form of nickel allergy to identify, recognition of varying presentations is critical as these can result in more chronic and severe symptoms, and can be misdiagnosed as atopic dermatitis.