Most cases of pityriasis rosea heal without treatment, although severe cases can be treated with an anti-inflammatory medication, according to WebMD. Doctors may prescribe antiviral medicines to shorten the duration of the rash.
Non-prescription treatments for pityriasis rosea include exposing the rash to sunlight, avoiding sweating, taking cool showers, taking an oatmeal bath and avoiding deodorant soaps. Other treatments include applying over-the-counter 1 percent hydrocortisone cream, taking an over-the-counter antihistamine and rubbing on moisturizer or calamine lotion, according to WebMD. The rash typically lasts six to eight weeks, although it can last as little as two weeks, according to the American Academy of Dermatology.