Psoriasis is a skin condition affecting some two per cent of the population, and occurs when the skin cells replace themselves too quickly. There are many different types, but the most common is chronic plaque psoriasis. The cause is unknown, but triggers are thought to include skin injury, sore throat or chest infections, certain drug treatments, sunburn and stress. A specific form of arthritis is related to psoriasis. Psoriasis usually appears as red, scaly patches that reveal fine silvery scales when scraped or scratched. These patches may itch and feel uncomfortable. It's most common on the knees, elbows and scalp, but can appear anywhere on the body.Some people with psoriasis become withdrawn and don't socialise or form relationships because of the way people react to the appearance of their skin. Treatment and self-help can however be effective, as this book shows.Topics include: Psoriasis and your health (arthritis; more rarely, other complications such as circulation and bowel problems); Treatments such as emollients, skin softeners and topical drug therapy applied to the skin, such as vitamin D derivatives, tar preparations, steroids, dithranol preparations and vitamin A derivatives; Ultraviolet B light therapy, systemic medication (methotrexate, ciclosporin, aitretin, hydroxycarbamide), and biologics designed to block specific molecules in the immune system that trigger development of psoriasis (etanercept, infliximab, efalizumab); Complementary therapies such as acupuncture, homeopathy and herbal therapy; Psoriasis in children; guttate psoriasis (a type common in children after a respiratory infection); and, Emotions and confidence.