Reactive perforating collagenosis: light, ultrastructural and immunohistological studies.

Reactive perforating collagenosis is an uncommon disorder and few accounts refer to ultrastructural features. This report includes a study by light and transmission electron microscopy of serially sectioned biopsies from early lesions in two patients. Immunohistological investigations utilizing antibodies to basement membrane, laminin, collagen and cytokeratin were also done. Collagen and elastin were demonstrated within the centre of the lesions and there was a defect in the basal lamina at the base of the lesion. The collagen, cytokeratin and the basal lamina in the lesions were antigenically similar to those in the surrounding normal skin. These results are compared with previous findings and discussed in the light of the current views on the pathogenesis of this disorder.