Difficulties in diagnosing pityriasis lichenoides et varioliformis acuta: A clinical case report

Background . Pityriasis lichenoides et varioliformis acuta, also known as Mucha-Habermann disease, is a benign form of parapsoriasis characterized by acute onset, widespread polymorphous inflammatory eruptions, and systemic symptoms. Rare disorders such as pityriasis lichenoides et varioliformis acuta present a diagnostic and therapeutic challenge that requires interdisciplinary expertise. Case description . The article presents a case of pityriasis lichenoides et varioliformis acuta in a boy referred for hospitalization at the Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology; the patient had recurrent episodes of bright erythematous, papular, and vesiculo-pustular centripetal eruptions, whose regression resulted in hypopigmentation and varioliform scarring. The performed dermoscopy revealed a pronounced vascular pattern, monomorphic dotted and linear vessels. The pathomorphological study confirmed the diagnosis of pityriasis lichenoides et varioliformis acuta. The typical clinical course of pityriasis lichenoides et varioliformis acuta coincided with an infectious process (enterovirus infection), which is also characterized by vesicular skin eruptions. Treatment recommended by pediatricians had no effect on the regression of skin eruptions. The average time from the appearance of eruptions to the correct diagnosis was about two months. Conclusion . PLEVA is a rare disorder, primarily developing in children, which makes its diagnosis a complex and time-consuming process. Infectious agents should be considered important disease triggers in children. It is believed that a favorable outcome and prolonged remission are characteristic of patients with the onset of the disease after the age of five years. Therefore, the follow-up of patients with the onset of the disease at the age of four years (on the example of this clinical case) should be carried out with the participation of pediatric specialists and dermatovenereologists throughout the entire cold season, when the risk of viral infections and pityriasis recurrence exists.