Pityriasis rosea is a common and typically self-limited and benign cutaneous eruption. Classically, a herald patch, a solitary 2-5 cm scaly, pink or skin-colored plaque with mild central clearing and a raised border appears first, often on the trunk. In children, the herald patch appears about 4 days prior to the widespread rash. The ensuing eruption consists of multiple discrete, oval, erythematous, and scaly plaques and patches oriented along skin cleavage lines (Langer's lines), most commonly on the trunk, abdomen, and neck. The extremities and face are usually spared. New lesions may continue to arise for 2-3 weeks.

Pityriasis rosea is usually pruritic in pediatric patients, although it may also be asymptomatic. Constitutional symptoms may precede the eruption, including irritability, fever, headache, sore throat, and cough. In most pediatric patients, the rash typically resolves within 2-6 weeks. Recurrence is rare.

Adolescents and young adults are most commonly affected. Pityriasis rosea is less common in children younger than 10 years, and it is rare in children younger than 2 years. An atypical form of pityriasis rosea, characterized by papular lesions and facial and scalp involvement, is more prevalent in Black children. In individuals with darker skin colors, hyperpigmentation can result upon resolution.

While the exact cause remains unclear, pityriasis rosea in children is thought to be associated with primary infection or systemic reactivation of human herpesvirus 6 and 7 (HHV-6 and HHV-7).

Certain drugs 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. Pityriasis rosea may also occur after vaccines, such as the COVID-19, smallpox, tuberculosis, and human papillomavirus (HPV) vaccines.