Attacks most often last 4 - 8 weeks. Symptoms may disappear by 3 weeks or last as long as 12 weeks.
The rash starts with a single large patch called a herald patch. After several days, more skin rashes will appear on the chest, back, arms, and legs.
The skin rashes:
Your health care provider can usually diagnose pityriasis rosea by the way the rash looks.
Rarely, the following tests are needed:
Habif TP. Psoriasis and other papulosquamous diseases. In: Habif TP, ed. Clinical Dermatology. 5th ed. Philadelphia, Pa: Mosby Elsevier;2009:chap 8.
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