History:

 Pityriasis lichenoides et varioliformis acuta (PLEVA) or also known as Mucha–Habermann disease is an acute dermitis with hemorrhagic crusted papules. Most patients are children or young adults. The cause is unknown, but viral triggers long suspected. Clinically, it may simulate varicella but has longer duration. It is characterized by sudden appearance of red-brown papules that rapidly develop hemorrhagic crusts. Sometimes necrotic, ulcerated, and heal with scars. Rarely associated with systemic signs and symptoms. Histologically, it is  prototype of lymphocytic vasculitis with dense wedge-shaped lichenoid infiltrate and vascular damage in upper dermis. 

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