[Association of lichen planus and discoid lupus erythematosus. A clinical and histopathological study of 2 cases].

Two patients showing features of both lichen planus and lupus erythematosus are described: reticular whitish patches in the oral mucosa coexisting with chronic, partly atrophic LED-like skin lesions located on the face were present in both of them. The histological, histochemical and immunopathological findings allowed to diagnose a "LP-LE coexistence" more than a mixed LP-LE disease. The clinical, histological and immunological relationships between LP and LE are discussed and it is suggested that the pathogenesis of the coexistence of the two diseases could be related to a common pathophysiological pathway. It might be that LP and LE are due to a single aetiological agent (e.g. a virus) interacting with different genetic backgrounds to cause LE in some, LP in others and an intermediate disease in a small group of patients. The histopathological and immunopathological features that distinguish LP from LE are the concentration of lymphocytes in areas of keratinocyte damage, the different colloid bodies patterns and the direct IF findings. The Authors conclude that further studies should be performed on "LP-LE coexistence".