Pityriasis Rubra Pilaris

ByShinjita Das, MD MPH, Massachusetts General Hospital
Reviewed/Revised Sep 2023
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Pityriasis rubra pilaris is a rare chronic skin disorder that causes thickening and yellowing of the skin, including the palms and soles, and red, raised bumps. The bumps may merge together to form red-orange, scaly patches (plaques) with areas of normal skin in-between.

The cause of pityriasis rubra pilaris is unknown.

The two most common forms of the disorder are

  • Juvenile classic

  • Adult classic

The juvenile classic form of pityriasis rubra pilaris is inherited and begins in childhood. The adult classic form of pityriasis rubra pilaris does not seem to be inherited and begins in adulthood.

Other nonclassic forms exist in both age groups. Sunlight, human immunodeficiency virus (HIV) infection or another infection, minor trauma, or an autoimmune disorder may trigger a flare-up.

Symptoms of Pityriasis Rubra Pilaris

Symptoms of pityriasis rubra pilaris include pink, red, or orange-red scaly patches that can develop on any part of the body and are usually itchy. The skin can become thick and yellow.

Pityriasis Rubra Pilaris
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Pityriasis rubra pilaris can cause thickening and yellowing of the palms and soles.
Image provided by Thomas Habif, MD.

Diagnosis of Pityriasis Rubra Pilaris

  • A doctor's evaluation

  • Skin biopsy

Doctors base the diagnosis of pityriasis rubra pilaris on how the scaly patches look and where they appear on the body.

Doctors sometimes take a sample of skin tissue and examine it under a microscope (biopsy) to rule out other disorders (such as seborrheic dermatitis in children and psoriasis).

Treatment of Pityriasis Rubra Pilaris

  • Medications applied to the skin (topical), taken by mouth (oral), or given by injection

  • Phototherapy

Treatment of pityriasis rubra pilaris is very difficult. Symptoms of the disorder may be lessened, but the disorder itself can almost never be cured. Classic forms of the disorder go away slowly over 3 years, whereas nonclassic forms last much longer.

To reduce scaling, doctors may give skin moisturizers (emollients) or have people apply lactic acid under a dressing that keeps air away from the skin (occlusive dressing), followed by corticosteroids applied to the skin.

Phototherapy

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