Pityriasis rosea

Last updated: April 26, 2023

Summarytoggle arrow icon

Pityriasis rosea is a self-limiting rash that most commonly affects young adults, especially females. Although the exact etiology is unknown, pityriasis rosea is thought to be triggered by viral infection. The majority of patients present with a solitary, coin-sized herald patch, followed by multiple, oval, scaly papules distributed in a classic Christmas tree pattern on the trunk. Except for mild pruritus, pityriasis rosea is asymptomatic. The lesions typically disappear within two months, often causing postinflammatory hyperpigmentation or hypopigmentation. Typically, only symptomatic treatment of pruritus with lotions, oral antihistamines, and/or a short course of topical steroids is necessary.

Epidemiologytoggle arrow icon

  • Age range: 10–35 years of age
  • Sex: > (reason unknown)

Epidemiological data refers to the US, unless otherwise specified.

Etiologytoggle arrow icon

  • Idiopathic
  • A viral etiology (HHV 6 and 7) is suspected based on the following: [1]
    • Pityriasis rosea can occur in clusters, affecting many people living in the same community.
    • Seasonal variations (more common in the spring and fall)
    • Preceded by a prodromal flu-like illness in some patients
    • Life-long immunity (recurrence is rare but possible)

Clinical featurestoggle arrow icon

  • Prodrome: (1–2 weeks prior to rash onset): flu-like symptoms (e.g., malaise, fever, pharyngitis)
  • Initial eruption (∼ 90% of cases): herald patch (mother patch)
    • Single ovoid macule or patch, 2–10 cm in diameter
    • Slightly raised, dark red border with a central salmon-colored clearing zone
    • Surrounded by a collarette: a collar of fine, white scales (like cigarette paper)
    • Typically on the back
  • Secondary eruption (2–21 days later)
    • Bilateral diffuse, oval-shaped, salmon-colored papules and plaques (< 1.5 cm) with scaly collarette
    • Papules appear along Langer lines, which align on the back like the branches of a Christmas tree (Christmas tree appearance)
    • Typically seen on the trunk (thorax, back, abdomen), neck, and upper extremities
  • Pruritus may occur in 25–75% of cases.
  • Postinflammatory hypopigmentation or hyperpigmentation (resolves over several months)

Diagnosticstoggle arrow icon

Differential diagnosestoggle arrow icon

The differential diagnoses listed here are not exhaustive.

Treatmenttoggle arrow icon

Complicationstoggle arrow icon

We list the most important complications. The selection is not exhaustive.

Referencestoggle arrow icon

  1. Drago F, Ciccarese G, Rebora A, Broccolo F, Parodi A. Pityriasis Rosea: A Comprehensive Classification. Dermatology. 2016; 232 (4): p.431-437.doi: 10.1159/000445375 . | Open in Read by QxMD
  2. Pityriasis Rosea. Updated: January 1, 2017. Accessed: May 16, 2017.
  3. Villalon-Gomez JM. Pityriasis Rosea: Diagnosis and Treatment.. Am Fam Physician. 2018; 97 (1): p.38-44.

Icon of a lock3 free articles remaining

You have 3 free member-only articles left this month. Sign up and get unlimited access.
 Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer