Oral hyposensitization in nickel allergy.

In two controlled studies, each including 24 patients with contact allergy to nickel, different protocols were designed in an attempt to diminish the patients' hypersensitivity by oral administration of the antigen. With doses of 5.0 mg nickel sulfate taken once a week for 6 weeks, but not with 0.5 mg daily, the degree of contact allergy was significantly lowered, measured as patch test reactions before and after nickel administration.