Pityriasis lichenoides et varioliformis acuta
（重定向自Acute pityriasis lichenoides）
Pityriasis lichenoides et varioliformis acuta (also known as "acute guttate parapsoriasis", "acute parapsoriasis", "acute pityriasis lichenoides", "Mucha–Habermann disease", "parapsoriasis acuta", "parapsoriasis lichenoides et varioliformis acuta", and "parapsoriasis varioliformis") is a disease of the immune system. It is the more severe version of pityriasis lichenoides chronica. The disease is characterized by rashes and small lesions on the skin. The disease is more common in males and usually occurs in young adulthood, although it has been seen in every age group and every race. It is possible for the disease to go into remission for short periods of time or forever.