Dithranol for psoriasis

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Dithranol for psoriasis


Generic NameBrand Name
dithranolAnthrascalp, Anthranol, Anthraforte

Dithranol comes as an ointment, a cream, or a lotion. For short-term therapy, dithranol is applied to the skin or scalp for 20 to 60 minutes once a day, then washed or shampooed off.

Treatment usually starts with a product that contains a small amount of the medicine. The amount is increased every few days as long as your symptoms are improving and you are not having side effects. If a lower-dose product is used, it can be left on the skin longer (often overnight) and washed off in the morning.

Dithranol can be used in combination with coal tar and ultraviolet B (UVB) therapy (Ingram regimen). It can also be combined with corticosteroids or calcipotriol.

How It Works

Dithranol limits the growth of skin cells.

Why It Is Used

Dithranol is used to treat large, scaly patches of psoriasis on the arms, legs, or torso that have not cleared up with other treatment.

How Well It Works

Used alone, dithranol can be effective over a period of a few weeks.

Dithranol is likely to be effective in 2 to 3 weeks when combined with ultraviolet (UV) light therapy (the Ingram regimen).1

Side Effects

Side effects of dithranol include:

  • Irritation and discoloration of the skin that is not affected by psoriasis. (Take care to apply the product only to the skin affected by psoriasis, not to normal skin.)
  • A purple-brown stain on the skin. The discoloured skin may go away within 3 weeks after you stop using the drug.
  • A deep red-brown colour of the skin, which develops from the inflammation of psoriasis. It may take weeks or months to go away.
  • Grey hair that turns pink when dithranol is used on the scalp.

Newer forms of dithranol have made staining less of a problem.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Dithranol may permanently stain fabrics, showers, countertops, sinks, and other materials.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.



  1. Gudjonsson JE, Elder JT (2008). Psoriasis. In K Wolff et al., eds., Fitzpatrick's Dermatology in General Medicine, 7th ed., vol. 1, pp. 169–193. New York: McGraw-Hill Medical.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer Alexander H. Murray, MD, FRCPC - Dermatology
Last Revised February 15, 2010

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