[Nickel-induced allergic contact dermatitis: reactivation by oral administration of hapten].

Recent reports suggest the high frequency of nickel induced allergic contact dermatitis and the absence in some patients of a clinical improvement following topical avoidance of sensitising allergen. In this study we evaluated the role of food ingested nickel in the maintenance and exacerbations of the disease. A high frequency of cutaneous exacerbations was obtained after oral challenge with a low nickel containing diet. These results suggest a pathogenetic role of nickel present in foods and indicate that an appropriate diet may be useful in the prophylaxis and in the therapy of nickel dermatitis in sensitized patients.