Simultaneous occurrence of lichen striatus in siblings.

Lichen striatus (LS) is a self-limiting linear papular dermatosis of unknown etiology seen mostly in children. We report LS occurring in two pairs of siblings: two sisters who had LS at an interval of 6 months and a brother and sister who had the dermatosis contemporaneously after an episode of flulike fever. In all four patients family history was positive for atopy. LS is frequently associated with atopic diseases. The abnormal immune status of patients with atopy may be a predisposing factor in the induction of LS. In our patients the simultaneous occurrence of LS in siblings after a flulike fever appears to corroborate the hypothesis that a viral infection is a possible candidate, as other authors have proposed. The rarity of familial cases of LS is, in our opinion, due to the exceptional confluence of difference sporadic events (atopy, viral infection caught at a specific period of life such as childhood, and a genetic predisposition) simultaneously present in the same patient.