An ultrastructural study of chronic chromate hand dermatitis

Occupational chromate dermatitis is one of the most common occupational diseases, predominantly causing hand eruptions. The ultrastructural manifestations of this condition have not been previously described. In this study, 7 cases of chronic occupational chromate hand dermatitis were investigated. Biopsies were taken from palmar skin and examined using light and electron microscopy. The ultrastructural features of chronic chromate dermatitis are similar to those of acute inflammatory dermatoses, even in the absence of clinical or histological features of an acute inflammatory process. Most changes are probably mechanical in nature and are a result of increasing intercellular oedema. Several features of chronic chromate dermatitis are common to other inflammatory dermatoses, including the presence of marked intercellular oedema of the lower epidermal keratinocytes, the formation of intracellular vacuoles in cells of the lower epidermis and the presence of milder ultrastructural changes in the midepidermis. The study has documented the presence of dendritic, spindle-shaped granular cells in the upper dermis, which have not previously been described in chromate dermatitis. The epidermis in chromate dermatitis appears to have fewer desmosomes when compared with other forms of dermatitis.