Contact urticaria to the MCU-2A/P gas mask.

A case of contact urticaria to the silicone rubber in the MCU-2A/P gas mask is presented. Contact urticaria is a type I hypersensitivity reaction mediated by immunoglobulin E that usually manifests as localized erythema, edema, pruritus, and urticarial plaques. It can also cause systemic reactions, including anaphylaxis. Allergic reactions to silicone rubber have been increasingly reported and are of importance in medical and military personnel. The implication of such a diagnosis in an active duty military member is significant because the individual cannot be worldwide-qualified. The correct diagnosis of allergic skin reactions to personal protective gear is critical to maintaining a strong fighting force and protecting military personnel from potentially life-threatening allergic reactions.