Pyodermite végétante of Hallopeau. Immunofluorescence studies performed in an early disease stage.

A 50-year-old woman with autoimmune thyroiditis had an eruption resembling pyodermite végétante as described initially by Hallopeau. Direct immunofluorescence microscopy studies indicated deposition of IgG and C3 in the intercellular area of the epidermis. Circulating IgG antibodies to the intercellular areas of stratified epithelial tissue were demonstrable on indirect immunofluorescence microscopy. Treatment with prednisone and azathioprine resulted in the disappearance of vetetating lesions and in healing, with postinflammatory hyperpigmentation. Immunofluorescence microscopy studies, in an early stage of the disease, are of great value in the diagnosis of pyodermite végétante of Hallopeau. Our findings support the view that pyodermite végétante of Hallopeau belongs immunologically to the pemphigus group.