Systemic Nickel Allergy Syndrome

Systemic nickel allergy syndrome (SNAS) is a syndrome characterized by both cutaneous and extracutaneous symptoms following the systemic exposure to nickel, most commonly through the ingestion of nickel-containing foods in individuals sensitized to nickel via skin contact. Patients with SNAS present with dermatitis in addition to gastrointestinal, neurological, and other extracutaneous symptoms. The most widely implemented treatment is the low-nickel diet. The present authors saw a patient with a history of allergic contact dermatitis to nickel experience resolution of hand dermatitis, chronic pain (diagnosed as fibromyalgia), and chronic diarrhea (diagnosed as irritable bowel syndrome) with a low-nickel diet after just one month. She was diagnosed with SNAS, and this intriguing case prompted the review which follows.