| Pityriasis rosea | |
|---|---|
| Other names | Pityriasis rosea Gibert[1] |
 | |
| Pityriasis rosea on the back showing a "christmas tree" pattern | |
| Specialty | Dermatology, infectious disease |
| Symptoms | Single red and slightly scaly area, followed |
| Usual onset | 10 to 35 years old[2] |
| Duration | Less than three months[2] |
| Causes | Unclear[3] |
| Diagnostic method | Based on symptoms[2] |
| Differential diagnosis | Tinea corporis, viral rash, pityriasis versicolor, nummular eczema[3] |
| Treatment | Supportive care[3][2] |
| Frequency | 1.3% (at some point in time)[3] |
Pityriasis rosea is a type of skin rash.[2] Classically, it begins with a single red and slightly scaly area known as a "herald patch".[2] This is then followed, days to weeks later, by an eruption of many smaller scaly spots; pinkish with a red edge in people with light skin and greyish in darker skin.[4] About 20% of cases show atypical deviations from this pattern.[3] It usually lasts less than three months and goes away without treatment.[3] Sometimes malaise or a fever may occur before the start of the rash or itchiness, but often there are few other symptoms.[3]
While the cause is not entirely clear, it is believed to be related to human herpesvirus 6 (HHV6) or human herpesvirus 7 (HHV7).[3] It does not appear to be contagious.[3] Certain medications may result in a similar rash.[3] Diagnosis is based on the symptoms.[2]
Evidence for specific treatment is limited.[3] About 1.3% of people are affected at some point in time.[3] It most often occurs in those between the ages of 10 and 35.[2] The condition was described at least as early as 1798.[1]
- ^ a b Bolognia, Jean L.; Jorizzo, Joseph L.; Rapini, Ronald P. (2003). Dermatology. Mosby. p. 183. ISBN 9789997638991.
- ^ a b c d e f g h "Pityriasis Rosea". NORD (National Organization for Rare Disorders). 2015. Retrieved 10 November 2017.
- ^ a b c d e f g h i j k l Eisman, S; Sinclair, R (29 October 2015). "Pityriasis rosea". BMJ (Clinical Research Ed.). 351: h5233. doi:10.1136/bmj.h5233. PMID 26514823. S2CID 33609874.
- ^ Onalaja, Amanda A.; Taylor, Susan C. (2021). "1. Defining skin color". In Li, Becky S.; Maibach, Howard I. (eds.). Ethnic Skin and Hair and Other Cultural Considerations. Switzerland: Springer. p. 10. ISBN 978-3-030-64829-9.