Elastic tissue changes in generalized granuloma annulare.

The histological picture in granuloma annulare (GA) is well defined. The types of infiltrate and the changes in collagen and elastic tissue have been repeatedly described. This is a preliminary study focused on the elastic tissue changes in lesions of generalized GA. Biopsies from four patients were studied. Specimens of involved and uninvolved skin from both exposed and unexposed parts of the body were compared. Changes of actinic elastosis in the papillary dermis in each patient in different stages were observed only in the exposed skin. The typical GA infiltrate was located beneath, in the upper mid-dermis. In the zone of the infiltrate in all specimens--exposed and unexposed--with no regard to the severity of actinic elastotic changes, absence or a marked reduction of elastic material was noted with engulfment of elastic remnants in giant cells. Giant cells with phagocytosis of elastotic material were mostly located on the periphery of the granuloma in the upper as well as in the deeper portion, where elastic fibers were still present. This might support the suggestion that degenerating elastic fibers promote the granulomatous reaction that leads to the formation of granuloma annulare.