ERYTHEMA-MULTIFORME-LIKE ERUPTION DUE TO TOPICAL CONTACTANTS - EXPRESSION OF ADHESION MOLECULES AND THEIR LIGANDS AND CHARACTERIZATION OF THE INFILTRATE

Erythema-multiforme-like reactions are a rare manifestation of allergi c contact sensitivity, the pathomechanisms of which and their possible relationship to erythema multiforme remain unclear. We present our hi stopathological and immunohistochemical findings regarding the express ion of several adhesion molecules and immunophenotypic markers of the infiltrate in skin biopsy specimens from 2 cases of erythema-multiform e-like reactions due to contact sensitizers and 3 cases of typical pos t-herpetic erythema multiforme. The histopathological pattern of eryth ema-multiforme-like reactions was characterized by an upper-dermal per ivascular lymphoid infiltrate with exocytosis and keratinocyte necrosi s; in 1 of the cases, there were foci of spongiosis and an admixture o f eosinophils in the infiltrate. In comparison with biopsy specimens f rom cases of typical erythema multiforme, in both cases of erythema-mu ltiforme-like reactions, the epidermal expression of ICAM-1 was more p rominent, the % of CD4(+) cells in the infiltrate was higher and the % of CD69(+) cells was lower. There were no other significant differenc es in the cell phenotype of the infiltrate or in adhesion molecule exp ression in biopsy samples from both disorders. (C) Munksgaard, 1995.