Verrucous lesion in patients with discoid lupus erythematosus. Clinical, histopathological and immunofluorescence studies.

Seven cases of classical discoid lupus erythematosus of the face associated with hyperkeratotic, papulo-nodular lesions on the arms and hands were studied. Clinically the hyperkeratotic lesions resembled keratoacanthomas or hypertrophic lichen planus. The clinical course was marked by chronicity, an absence regression of the lesions, and resistance to treatment. Histopathologically, a lichenoid cellular reaction seemed to play a key role in the development of the hypertrophic lesions which resembled either keratoacanthomoas or hypertrophic lichen planus. Elastic fibres were prominent in the upper dermis, the lower levels of the epidermis and in the hyperkeratotic horny layer. Immunofluorescence of the papulo-nodular lesions demonstrated the deposition of IgG and IgM in a globular pattern at the dermal-epidermal junction. Discontinuous deposition of these antibodies was also seen at the basement membrane zone. On the basis of the immunofluorescence, histopathological and clinical studies, we suggest that the verrucous, hyperkeratotic lesions on the upper extremities represent an unusual, but distinct, form of discoid lupus erythematosus.