Tars for Psoriasis
|Generic Name||Brand Name|
|Coal tar||Doak Oil, Exorex, Psoriasin|
|Coal tar shampoos||Denorex, Neutrogena T/Gel, Psoriasin S/A, Polytar|
Tar products that are used to treat psoriasis come in several forms. Coal tar is available as a gel, cream, ointment, liquid, or shampoo. You can get most tar products without a prescription.
Tar therapy usually starts with a product that contains only a small amount of tar. The amount may be increased every few days (unless your symptoms aren’t improving or you have side effects).
Tar products may be used with ultraviolet B (UVB) light therapy. This is called Goeckerman treatment. This combination may be given to a person who is in the hospital, usually over a period of 2 to 3 weeks. It may also be given in sessions at a doctor’s office or at home. A session usually lasts 8 hours, and 1 to 6 sessions a week are needed.
The Ingram regimen combines bathing with a coal tar product, applying dithranol cream, and getting UVB light therapy. The treatment takes about 3 weeks and can be done in the hospital or in a day treatment program.
How It Works
Coal tar makes psoriasis plaques thinner and less red.
Coal tar helps improve the effectiveness of other treatments, such as ultraviolet light or corticosteroid creams.
Why It Is Used
Coal tar products are used to treat mild or severe psoriasis plaque that affects small areas of the skin.
When psoriasis covers more of the body, tar may be used together with UVB light therapy.
How Well It Works
Tars have been used to treat psoriasis for many years, but studies disagree about how well they work. 1
In general, tar together with UVB light is thought to work better than tar alone.
Coal tar preparations are generally thought to be safe. There have been some concerns of cancer-causing chemicals in coal tar. But the U.S. Food and Drug Administration (FDA) reports that the chemical concentrations in over-the-counter coal tar are at safe levels. Use coal tar carefully when the skin rash is inflamed or is near the eyes or in skin folds.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
Coal tar therapies are messy and time-consuming.
- Naldi L, Rzany B (2009). Psoriasis (chronic plaque), search date August 2007. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
Last Revised: August 5, 2013
Author: Healthwise Staff
Medical Review: Adam Husney, MD – Family Medicine & Donald Sproule, MDCM, CCFP – Family Medicine & Amy McMichael, MD – Dermatology