This third article in a seven-part series looking at the identification and treatment of psoriasis, explores the active ingredients and action of the main topical treatments for psoriasis. Community nurses are perfectly placed to help patients take control of their skin condition, particularly in advising them on the benefits of topical treatments, which as they can be applied directly to the skin, allow the area to be targeted, lowering the level of absorption into the bloodstream and reducing side-effects (Psoriasis and Psoriatic Arthritis Alliance (PAPAA, 2017a).