BMJ Group Medical Reference
Some good research has shown that dithranol cream can improve psoriasis patches in about six weeks. Your doctor may recommend this treatment if you've tried a vitamin D cream, but it hasn't helped or it irritated your skin. 
Brand names for the cream include Dithrocream and Micanol. You'll need a prescription from your doctor for this treatment.
You put dithranol cream on your psoriasis patches for 15 to 60 minutes and then wash it off. You'll need to check with your doctor about how long you should keep it on your skin. Also, you need to apply this cream carefully to avoid soreness around the treated areas of your skin.
We found one summary of the research (a systematic review) that looked at three small studies on dithranol.  The summary showed that dithranol can improve your psoriasis if you apply it every day for several weeks.
Dithranol may stain your skin, clothes, bedding, and bath. The normal skin around the patches can get inflamed and sore. You should protect your hands with gloves when you put on dithranol, or wash your hands well afterwards.
Inflammation is when your skin or some other part of your body becomes red, swollen, hot, and sore. Inflammation happens because your body is trying to protect you from germs, from something that's in your body and could harm you (like a splinter) or from things that cause allergies (these things are called allergens). Inflammation is one of the ways in which your body heals an infection or an injury.
A systematic review is a thorough look through published research on a particular topic. Only studies that have been carried out to a high standard are included. A systematic review may or may not include a meta-analysis, which is when the results from individual studies are put together.
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