Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 6-12: Pityriasis Rosea + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Oval, fawn-colored, scaly eruption following cleavage lines of trunk Herald patch precedes eruption by 1–2 weeks Occasional pruritus +++ General Considerations ++ Common mild, acute inflammatory disease that is 50% more common in women The eruption usually lasts 6–8 weeks and heals without scarring +++ Demographics ++ Young adults are principally affected, mostly in the spring or fall + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Diagnosis is made by finding one or more classic lesions The lesions consist of oval, fawn-colored plaques up to 2 cm in diameter The centers of the lesions have a crinkled or "cigarette paper" appearance and a collarette scale, ie, a thin bit of scale that is bound at the periphery and free in the center Only a few lesions in the eruption may have this characteristic appearance, however Lesions follow cleavage lines on the trunk (so-called Christmas tree pattern), and the proximal portions of the extremities are often involved Herald patch precedes eruption by 1–2 weeks Pruritus, if present, is usually mild Variants that affect the flexures (axillae and groin), so-called inverse pityriasis rosea, and papular variants, especially in black patients, also occur +++ Differential Diagnosis ++ Secondary syphilis Tinea corporis (body ringworm) Seborrheic dermatitis Tinea versicolor (pityriasis versicolor) Lichen planus Guttate or plaque psoriasis Nummular eczema Drug eruption Viral exanthem + Diagnosis Download Section PDF Listen +++ ++ Clinical + Treatment Download Section PDF Listen +++ +++ Medications ++ See Table 6–2 Often requires no treatment In darker-skinned individuals, in whom lesions may remain dyspigmented for some time, more aggressive management may be indicated Oral acyclovir may improve the rash appearance The most effective management consists of daily UVB treatments for a week, or a short course of prednisone Topical corticosteroids of medium strength (triamcinolone 0.1%) and oral antihistamines may also be used if pruritus is bothersome + Outcome Download Section PDF Listen +++ +++ Prognosis ++ Usually acute self-limiting illness that disappears in about 6 weeks +++ When to Refer ++ If there is a question about the diagnosis, if recommended therapy is ineffective, or if specialized treatment is necessary + References Download Section PDF Listen +++ + +Contreras-Ruiz J et al. Interventions for pityriasis rosea. Cochrane Database Syst Rev. 2019 Oct 30;2019(10). [PubMed: 31684696] + +Urbina F et al. Clinical variants of pityriasis rosea. World J Clin Cases. 2017 Jun 16;5(6):203–11. [PubMed: 28685133]