Inflammatory cells in skin lesions of scabies

Cell infiltrates of biopsy specimens from nodular or papulovesicular skin lesions of seven patients with scabies were characterized by α-naphthyl acetate esterase (ANAE) staining and immunoperoxidase labelling. T lymphocytes were the dominant cells in the dermal inflammatory infiltrates of both nodular and papulovesicular lesions. Their mean proportion in the deeper dermal infiltrates was 64% and in the papillary infiltrates 42%. However, they were few in number around the burrows in the epidermis. In contrast, macrophages were frequent in the epidermis and papillary dermis, where they accounted for 47% and 25% respectively of all mononuclear cells. Immunoperoxidase staining revealed immunoglobulin-positivc plasma cells (from 1% to 10%, of all mononuclear cells) only in the dermal infiltrates of nodular lesions. IgE-positive plasma cells were encountered in all four specimens. These results emphasize the importance of macrophages in scabies infestation and suggest that a local IgE-mediated antibody response may occur in nodular lesions of scabies.