Acrodermatitis enteropathica (AE) is a rare disease of autosomal recessive inheritance which is presently recognized as a disorder of zinc homeostasis. The syndrome is mainly characterized by acral and periorificial skin lesions, alopecia, and gastrointestinal disturbances. Brandt 1 first described this constellation of symptoms in 1936, but the present denomination was proposed by Danbolt and Closs 2 in 1942. Moynahan 3 in 1973 recognized similarities between symptoms in AE and those found in experimental animal zinc deficiency. Subsequently, biochemical studies confirmed the hypothesis that AE was the phenotypic expression of severe zinc deficiency in humans and the administration of zinc supplements induced remission of signs and symptoms and correction of biochemical abnormalities. 4 These findings provided a marked improvement in the treatment of this often serious disorder and also stimulated interest in the physiological functions of zinc in man. Severe zinc deficiency of nutritional origin was reported by Kay and Tasman-Jones 5 in 1975 in patients who developed symptoms of AE while being parenterally nourished with solutions of low zinc content. Since that report the term AE has been freely applied to any severe zinc deficiency state where skin lesions and diarrhea occur. In the inherited form of AE the pathogenesis and implications for treatment differ markedly from those of the acquired forms of zinc deficiency which might best be called nutritional or symptomatic zinc deficiency. Present knowledge on the pathogenesis and treatment modalities for both the inherited and acquired forms of zinc deficiency will be discussed.