Pityriasis rosea is a skin rash believed to be caused by a virus. 

It generally affects young adults, especially in autumn and spring. 


The first signs of it is a circular pink rash, usually on the chest, known to doctors as a ‘herald patch’[1]. There may also be a smaller patches of a pink, scaly inflamed rash in the upper body and over the area of the ribs in lines, in the distribution of a ‘christmas tree’ pattern.


It generally occurs just once, with only a two per cent chance of getting it again[2].  The rash may last several months, but after the rash has gone, there are usually no scars are left. People with darker skin may have areas of skin discolouration for some time longer. 


Pityriasis rosea is not said to be contagious.     


Other skin conditions which may mimic pityriasis rosea include the fungal skin infection tinea (also known as ‘ringworm’).


Treatment for pityriasis rosea may include, but not limited to[2]:

  • ultraviolet light, so some mild sun may be beneficial
  • phototherapy using UVB ultraviolet light may be helpful. 


[1] https://www.healthdirect.gov.au/pityriasis-rosea

[2] https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/pityriasis-rosea


References:

Australasian College of Dermatologists (Pityriasis rosea) 

Cochrane Summaries (Interventions for pityriasis rosea, skin rash of unknown cause)

Johns Hopkins Medicine (What is pityriasis rosea?)

Mayo Clinic (Pityriasis rosea)