The condition often begins as a large single pink patch on the chest or back. This patch may be scaly and is called a “herald” or “mother” patch. Often the person with this condition will think this patch is ringworm and will apply creams used to kill the fungus. This will not help since the rash is not caused by a fungus. Within a week or two, more pink patches, sometimes hundreds of them, appear on the body and on the arms and legs. Patches may also occur on the neck, and though rare, the face. Occasionally there may be other symptoms, including tiredness and aching. The rash usually fades and disappears within six to eight weeks, but can sometimes last much longer.
The cause is unknown. It is not caused by a fungus or bacteria. It also is not due to any type of allergy. Pityriasis rosea is not a sign of any internal disease. A virus may cause this rash. Like other known viral diseases, pityriasis rosea usually occurs only once in an individual, and occasionally makes someone feel slightly ill. But the virus theory has not been proven. Unlike many viruses, however, pityriasis rosea does not seem to spread from person-to-person.
Your dermatologist will examine the affected area(s) and may order blood tests, scrape the skin or take a sample from one of the spots (skin biopsy). Treatment may include external or internal medications for itching. Soothing medicated lotions and lubricants may be prescribed. Occasionally anti-inflammatory medications, such as corticosteroids, may be necessary to stop itching or make the rash go away. Patients should be reassured that this disease is not a dangerous skin condition even if it occurs during pregnancy.