RESUMO
BACKGROUND: Erythema multiforme is an inflammatory disorder of the skin which may be characterized by erythematous papules, plaques, vesicles, and 'target-like' annular lesions. Mucosal lesions may occur. Symmetric irivolvement of the extrernities, especially the dorsurn of the hands and feet, and face is the classic pattern of cutaneous distribution. Palmoplantar lesions of erythema multiforme are relatively uricornmon. OBJECTIVE: Our purpose was to investigate the clinical and histopathological characteristics of erythema multiforme involving the palm and sole. METHODS: Thirty one cases of erythema multiforme involving the palm and sole, and thirty cases involving other sites wer collected and analysed with particular reference to epidemiological data, type and distribution of the skin lesion and histopathological characteristics. RESULTS: 1. The median ages of both groups were the early thirties. There were no sexual predominances. 2. The clinical features of erythema multiforme involving the palm and sole were relatively mild and showed atypical skin lesions including macules and papules compared with erythema multiforme involving the other sites. 3. The histopathological changes of the palmoplantar group were also mild, especially the epidermal changes which included keratinocytes necrosis, subepidermal blisters, focal parakeratosis, extensive epidermal necrosis and xocytosis etc. 4. The most important and consistent histopathological finding of the palmoplantar erythema multiforme group was lymphocyte tagging along the basernent membrane, which was found consistently apart from one case. CONCLUSION: We investigated the clinical and histopathological features of erythema multiforme involving the palm and sole. They showed mild clinical features and atypical skin lesions cornpared with other group. The histopathological spectrum of this group was diverse, and reflected the early stage of pathomecha nisms of erythema multiforme. Among them, lyrnphocyte tagging was the most important and censistent finding in palmoplantar erythema multiforme.
