Dermo-epidermal relationships in pyogenic granulomata.

The epidermis of pyogenic granulomata is presented with an unusual problem of distorted dermoepidermal relationships. In this study we have attempted to delineate the problem and have studied the way in which the epidermis copes with its difficulties. Sixteen pyogenic granulomata with (where possible) paralesional skin (and for comparison ten Campbell de Morgan spots) were studied by cell kinetic techniques. High labelling indices were found in the epidermis and in the endothelium in the pyogenic granulomata (contrasting strikingly with the findings in the Campbell de Morgan spots). A variable morphological response was found ranging from hyperplasia with parakeratosis to epidermal thinning and atrophy. Possible mechanisms for the epidermal changes are discussed and it is suggested that the data produced from this and similar studies may aid the understanding of dermo-epidermal interaction in a variety of common skin disorders including psoriasis.