Adult Blaschkitis With Lichenoid Features and Blood Eosinophilia

Abstract

There have been many reports of congenital and acquired dermatoses that trail Blaschko lines. Lichen striatus is representative of an acquired cutaneous linear inflammatory dermatosis running along the lines of Blaschko, characterized histopathologically by the predominance of lichenoid infiltration. Adult blaschkitis, however, is considered under the same disease spectrum as lichen striatus and is characterized by a spongiotic reaction pattern. Few differences have been recognized between lichen striatus and adult blaschkitis such as age of onset, triggers, distribution, histopathology, and response to treatment.A case of male patient with adult blaschkitis presenting as unilateral asymptomatic erythematous edematous papules, papulovesicles, and plaques over Blaschko's lines, in which skin biopsy revealed coexistent pathological features of lichen striatus and adult blaschkitis along with blood eosinophilia, has been presented here. This may add to the cumulative evidence on the pathogenesis of adult blaschkitis as an allergic reaction to an unknown inciting allergen.Evidence to consider adult blaschkitis as part of the lichen striatus spectrum is growing. Triggers for such skin reactions remain diverse. This case presentation suggests that adult blaschkitis could be triggered by an allergic response evidenced by the blood eosinophilia when other causes of eosinophilia are excluded.

Lichen striatus or Blaschkitis: About a new observation

“…The term adult blashkitis was first introduced by Grosshans and Marot, in 1990 to describe a cutaneous rash smilar to LS in an adult [1]. Blaschkitis affects adults preferentially, it it appears as a papulo-vesicular eruption most often located on the trunk and which follows a spontaneously favorable evolution with frequent relapses histology is in favor of a spongiotic dermatitis [2]. on the other hand, lichen striatus is most often seen in children and is rarely seen in adults, it more frequently located on the limbs as a papular rash without vesicles.…”