Pityriasis rosea is a common and typically self-limited cutaneous eruption. Classically, a herald patch, a 1-3 cm solitary scaly, pink or skin-colored plaque with mild central clearing and a raised border appears first, often on the trunk, up to 2 weeks prior to the widespread rash. The ensuing eruption consists of multiple discrete oval, erythematous, and scaly plaques and patches oriented along skin cleavage lines, most commonly on the trunk, upper extremities, and upper thighs. The face, scalp, forearms, palms, legs, and soles are usually spared. More lesions may erupt for up to 6 weeks.

Pityriasis rosea is usually pruritic but may also be asymptomatic. Constitutional symptoms may precede the eruption, including fever, headache, cough, and arthralgia. In most patients, the rash typically resolves within 12 weeks. Recurrence is rare.

Adolescents and young adults are most commonly affected, and it rarely occurs in children younger than age 10 years. Of note, pityriasis rosea occurring during pregnancy has been associated with increased risk of fetal demise and miscarriage, particularly if the lesions appear within the first 15 weeks of gestation. In pregnant individuals, the eruption may present in a more widespread distribution compared with classic pityriasis rosea and may be associated with systemic symptoms such as fatigue, headache, and loss of appetite. Close obstetric follow-up of pregnant patients with pityriasis rosea is recommended.

While the exact cause remains unclear, pityriasis rosea is thought to be associated with human herpesvirus 6 and 7 (HHV-6 and HHV-7) infection.

Certain drugs, such as captopril, clonidine, omeprazole, NSAIDs, metronidazole, terbinafine, lamotrigine, ibrutinib, domperidone, and dupilumab, among many others, can cause a pityriasiform eruption that resembles pityriasis rosea. Drug-related pityriasis rosea-like lesions may appear more red-violet in color, typically do not present with a herald patch, and may be associated with eosinophilia. Eruptions may also occur after vaccines, such as the COVID-19, smallpox, tuberculosis, and human papillomavirus (HPV) vaccines.