Classic pityriasis rosea

P ityriasis rosea is an acute inflammatory skin disorder characterized by papulosquamous skin lesions that appear on the trunk and extremities. The disease affects children and adults, involving slightly more females than males [1]. Pityriasis rosea is known to complicate viral infections, especially human herpes virus type 7 (HHV-7) [2]. However, other viruses have been described, including influenza virus (H1N1) and more recently SARS-CoV-2 [3]. Skin manifestations in pityriasis rosea are generally preceded by a prodrome of headache and malaise. In most cases, skin eruption starts on the upper trunk (chest or back) with the so-called . A few days later, smaller round lesions appear on the rest of the trunk and extremities. Lesions are rarely itching in nature and the disease passes asymptomatically. Skin eruptions fade slowly in the course of days, leaving no or slight pigmentation of the skin. Complete disappearance of skin lesions may take several weeks, whereas skin dyspigmentation might last for weeks to months. The diagnosis of pityriasis rosea is straightforward and based mainly on clinical findings with suitable time course. There is no specific treatment for pityriasis rosea. A Cochrane based meta-analysis of 14 trials that evaluated the effects of treatment with antibiotics, antivirals, phototherapy, antihistamines, and Chinese medicines, found only moderate evidence supporting acyclovir treatment for improving itchingin comparison to placebo or no treatment [4]. In total 761 patients (age range 2–60 years) were included in the studies.