Psoriasis is a chronic, noncommunicable, painful, disfiguring and disabling disease characterised by the occurrence of raised, red, scaly patches on the skin that can itch or sting. Psoriasis can appear anywhere on the body but mostly occurs on the outside of the elbows, knees or scalp. There are five different types of psoriasis: plaque psoriasis, guttate psoriasis, inverse psoriasis, pustular psoriasis and erythrodermic psoriasis. Plaque psoriasis is the most common. Psoriasis affects men and women of all ages and ethnicity worldwide. There are few studies on the incidence of psoriasis, however there is evidence to suggest that the prevalence of psoriasis may be increasing.... Read more » Many studies have demonstrated that psoriasis can impact substantially on quality of life, even when a relatively limited body surface area is affected.