%0 Journal Article %T Mimetismo antig¨ºnico seguido de espalhamento de ep¨ªtopos: agente desencadeador patog¨ºnico da morfologia cl¨ªnica do l¨ªquen plano e de sua transi£¿£¿o para a S¨ªndrome de Graham-Little-Piccardi-Lassueur e para a ceratose l¨ªquen¨®ide cr£¿nica - Hip¨®tese m¨¦dica ou realidade? %A Tchernev %A Georgi %A Nenoff %A Pietro %J Anais Brasileiros de Dermatologia %D 2009 %I Sociedade Brasileira de Dermatologia %R 10.1590/S0365-05962009000600019 %X literature data analysis, providing an exact explanation of the lichen planus pathogenesis, as well as its transition into other rare forms such as keratosis lichenoides chronica or graham lassueur piccardi little syndrome are scant, or totally missing. the chronological course of the disease, known in the literature as lichen planus, varies. some patients develop lichen planus or lichen nitidus and there is no logical explanation why. it is also not clear why single patients initially develop ulcerative lesions in the area of the mucosa and only in a few of them these lesions affect the skin. antigen mimicry and epitope spreading could be the possible pathogenic inductor in cases of lichenoid dermatoses, as well as the cause for their transition into ulcerative, exanthematous or other rare forms. the epitope spreading is probably not the leading pathogenetic factor in lichen planus but a phenomenon which occurs later. this manuscript analyzes some basic pathogenic aspects and presents some possible medical hypotheses regarding the heterogenic clinical picture and pathogenesis of lichen planus and lichenoid like pathologies of the skin which, in the near future should be analyzed in details in order to clarify several dilemmas the clinical dermatologist has to face. %K apoptosis %K epitopes %K immunity %K infection %K lichen planus %K molecular mimicry. %U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0365-05962009000600019&lng=en&nrm=iso&tlng=en