Chronic zinc toxicity in an infant who received zinc therapy for atopic dermatitis

In Japan and many other industrialized countries, zinc is readily available as a nutritional supplement, for cosmetic purposes and for the treatment of atopic dermatitis. The potential risks associated with its use are not, however, fully recognized. As a reciprocal relationship exists between copper and zinc, excessive zinc can produce hypocupraemia, which can cause anaemia and neutropenia. We report on a male infant who presented with anaemia and neutropenia and showed signs of developmental delay after dietary restriction for food allergy and eating difficulties and zinc therapy administered for the treatment of atopic dermatitis at a dose nine times the daily dietary allowance for his age group. After 1 mo of zinc withdrawal, copper and ceruloplasmin concentrations had increased, and the blood cell count had improved, activity was increasing but verbal development remained limited. As development improved after withdrawal of zinc, we cannot rule out a relation between developmental delay and hyperzincaemia and/or hypocupraemia.

Caution must be exercised in administering zinc to children during their neurological development.