Coal tar is a thick black liquid made by heating coal at very high temperatures under anaerobic conditions. Coal tar has a long history as a topical treatment of skin conditions, including atopic dermatitis. Coal tar comes in different concentrations in various formulations, and contains a large number of different beneficial substances.
A recent study compared the effectiveness of a coal tar cream with a corticosteroid cream in people with mild-to-moderate atopic eczema. The participants used the creams twice daily over a period of four weeks, and the results showed that both treatments were equally effective in relieving the symptoms of their eczema1. In a review it was concluded that most studies (21 of 25) supported the use of coal tar products in atopic dermatitis (and/or psoriasis), but also that the level of evidence is not strong2. HelloSkin’s experts were unable to find the studies that were included in this review. A number of studies expected to provide further information on this are ongoing.
The concentration of an ingredient is important for its efficacy, and therefore products containing the same ingredient may not necessarily have the same effect as in the studies mentioned above.
Updated: July 2017