From the Research
Pityriasis rosea is a common, self-limiting skin condition that typically resolves without treatment within 6-8 weeks, and the primary approach should be reassurance and symptomatic treatment, with acyclovir being the best option for patients with extensive, persistent lesions or systemic symptoms, as supported by the most recent and highest quality study 1.
Description of Pityriasis Rosea
Pityriasis rosea is characterized by a distinctive rash that typically begins with a single, larger "herald patch" followed by smaller, oval-shaped, salmon-colored lesions with a fine scale that often follow skin lines in a "Christmas tree" pattern on the trunk and proximal extremities. The condition primarily affects adolescents and young adults.
Treatment of Pityriasis Rosea
Treatment is mainly symptomatic, focusing on relieving itching with oral antihistamines, topical corticosteroids, and moisturizers. For severe cases, UVB phototherapy may be considered. Acyclovir is recommended for patients with extensive, persistent lesions or systemic symptoms, as it has been shown to be the most effective treatment option in a network meta-analysis 1.
Differential Diagnosis
The differential diagnosis includes:
- Tinea corporis (which typically has more active, raised borders and responds to antifungal treatment)
- Secondary syphilis (check for palmar/plantar involvement and obtain serologic testing)
- Drug eruptions (review medication history)
- Viral exanthems (consider associated systemic symptoms)
- Psoriasis (more well-defined plaques with thicker scale)
Etiology and Prognosis
Pityriasis rosea is thought to be triggered by viral reactivation, particularly human herpesvirus 6 and 7, explaining its self-limiting nature and lack of contagiousness. Patients should be reassured about the benign course of the condition and informed that recurrence is rare. The most recent and highest quality study 1 supports the use of acyclovir as the best treatment option for patients with pityriasis rosea, and this should be considered in clinical practice.