Pityriasis rosea is an acute, self-limited exanthematous skin disease.
It most commonly affects adolescents and young adults, characterized by the appearance of a single “herald patch” followed days to weeks later by a generalized eruption of oval, erythematous, scaly lesions that often follow the skin’s cleavage lines in a “Christmas tree” pattern on the trunk.
They often follow Langer’s lines, creating a “Christmas tree” pattern
Secondary eruption occurs 1–2 weeks later with multiple smaller oval patches or plaques appear on the trunk and proximal limbs
Its etiology is not fully understood.but reactivation of human herpesvirus 6 or 7 (HHV-6/7) is strongly implicated in many cases.
The herald patch is typically a solitary, round or oval, pink or salmon-colored plaque with a collarette of scale, usually on the trunk.
Within 1–2 weeks, multiple smaller lesions appear.
Pruritus is common but variable.
The rash usually resolves spontaneously within 6–8 weeks, though it can last up to several months.
Pityriasis rosea is generally benign.
It can be associated with prodromal symptoms of malaise, fever, sore throat and, rarely, complications in pregnancy.
It is not contagious.
The differential includes secondary syphilis, tinea corporis, drug eruptions, and viral exanthems.
Treatment is supportive, focusing on symptom relief with topical corticosteroids or antihistamines; antivirals or phototherapy may be considered in severe or persistent cases.
Symptoms include: Mild itching (may be absent or intense) Low-grade fever or malaise (rare) Lesions usually last 6–8 weeks, sometimes up to 3 months
It is self-limiting, and treatment focuses on symptom relief: Topical corticosteroids → for itching or inflammation Antihistamines → for pruritus Moisturizers → soothe skin Sunlight or UV therapy may speed resolution in some cases Avoid irritants (harsh soaps, hot showers)