Histopathological study of transient acrodermatitis enteropathica due to decreased zinc in breast milk.

Two children, one born prematurely and the other born at full term developed acrodermatitis enteropathica due to marginal or low levels of zinc in their mothers' breast milk. Skin from both patients was studied with light and electron microscopy. The most characteristic light microscopic features were parakeratosis, absence of the granular layer, and pallor of the upper epidermal cells. Normal flattening of the upper Malphighian cells did not occur. Electron microscopic examination revealed that keratohyalin was decreased to absent, and the upper malpighian cells were edematous with vacuoles and large numbers of ribosomes, but small numbers of tonofilaments. Large amounts of keratinosome-derived-lamellae were found in the intercellular spaces in the keratinization area. The keratinosome-derived-lamellae were focally intermingled with opaque lipid plaques or myelin figures, probably derived from keratinosomes. The electron microscopic findings show abnormal keratinization and suggest that it is related to a disturbance of keratinosome metabolism due to zinc deficiency.