Lichenoid eruptions are represented by lichen planus and lichen striat
us. They are characterized clinically by a papulous eruption, and hist
ogically by a dermal superficial infiltrate of lymphocytic cells and a
cytotoxic reaction directed against basal keratinocytes. The main dif
ferential diagnosis is hamartoma, the differentiation being important
because of the possible association of haemartoma with malformations.
(C) 1998, Elsevier, Paris.