Pityriasis Rosea - Western SummaryWestern Medicine Summary

Western Medicine

Western Summary

Pityriasis rosea is a skin rash that is estimated to affect 1.3% of the population.[1] The rash typically develops on the upper body on the back, chest, and abdomen. 


Pityriasis rosea refers to a skin rash that is most commonly characterized by pink to salmon colored, mildly scaly flat and slightly raised lesions on the trunk and arms. At the beginning of the rash, there is often a single large round lesion that is referred to as the “herald patch.” This first herald patch signals that a more widespread eruption is about to follow. The following outbreak of lesions tends to occur along oblique skin lines radiating from a central axis on the trunk, in a pattern that has classically been categorized as a “Christmas tree” distribution. Children and young adults are more commonly affected.[2] 


There is no specific known cause for pityriasis rosea, but some viral infections and medications have been theorized to be a cause.[2]  


Often no treatment is required and the condition will resolve on its own over the course of weeks. If itch is associated with the skin eruption, anti-itch moisturizers or topical steroids might be helpful. 

  • Steroids: Topical steroids can be helpful in reducing inflammation.
  • Antihistamines: The itching may be treated with antihistamines. 
  • Light based therapy: Ultraviolet light type B may be used to treat pityriasis rosea.[2]

1.    Chuh A, Zawar V, Law M, et al. Gianotti-Crosti syndrome, pityriasis rosea, asymmetrical periflexural exanthem, unilateral mediothoracic exanthem, eruptive pseudoangiomatosis, and papular-purpuric gloves and socks syndrome: a brief review and arguments for diagnostic criteria. Infect Dis Rep.2012;4(1):e12; PMID: 24470919.

2.    Eisman S, Sinclair R. Pityriasis rosea. BMJ.2015;351:h5233; PMID: 26514823.