Type 1 and type IV hypersensitivity to nickel.

We report a case of type 1 and type IV contact hypersensitivity to nickel. Very few cases of immediate contact urticaria to nickel have been reported. The mechanism behind this is not fully understood, although it has been postulated that nickel may act as a mast cell discharger on a non-immunological basis. Nickel is found in varying concentrations in stainless steels; its biological availability varies depending on the alloy composition. Our patient has adapted her lifestyle to minimize her contact with household appliances containing nickel. If medical or dental treatment using stainless steel equipment is required, we recommend a short course of oral corticosteroids and antihistamines.