Dithranol Preparations
Before the discovery of more cosmetically acceptable treatments such as emollients and topical steroids, dithranol (also known as anthralin) was the main treatment for psoriasis for over 80 years. It is available in different strengths and preparations.
Dithranol preparations are almost always used for short periods of time (between 10 and 60 minutes). This helps to reduce their side effects such as skin irritation and staining of the skin.
How does it work?
Dithranol reduces the rapid skin cell production that is associated with psoriasis.
When is it used?
Dithranol is used to treat mild-to-moderate long-term psoriasis. It can also be used to treat psoriasis on the scalp.
How is it administered?
Dithranol preparations are applied directly to patches of psoriasis on the skin. They are administered once a day to the skin or scalp. Dithranol should be left on the affected area for up to an hour as directed by your healthcare team, and then washed off. This is known as short contact therapy.
Treatment is increased in strength every three to five days and should be used until the patch of psoriasis disappears. If your psoriasis does not respond to short contact therapy you can have dithranol administered for longer periods of time at a hospital. Your healthcare team will advise the strength of your treatment and how long you should leave it on for.
Advantages and disadvantages
A six-week course of treatment with a dithranol preparation may lead to clearing of psoriasis (but psoriasis can return).
The most common side effect of dithranol preparations is skin irritation; they may also cause a burning sensation if used at higher doses or if left on the skin for too long. They are not recommended on sensitive areas of skin including the face. Dithranol preparations will stain the skin, clothes and furniture.
If you have any questions about Dithranol preparations, you may want to discuss them with a member of your healthcare team.