<unk>  is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, or purple on some people with darker skin, dry, itchy, and scaly.<unk>  varies in severity from small, localized patches to complete body coverage. Injury to the skin can trigger<unk> oriatic skin changes at that spot, which is known as the Koebner phenomenon. The five main types of<unk>  are plaque, guttate, inverse, pustular, and erythrodermic. Plaque<unk> , also known as<unk>  vulgaris, makes up about 90% of cases. It typically presents as red patches with white scales on top. Areas of the body most commonly affected are the back of the forearms, shins, navel area, and scalp. Guttate<unk>  has drop-shaped lesions. Pustular<unk>  presents as small, noninfectious, pus-filled blisters. Inverse<unk>  forms red patches in skin folds. Erythrodermic<unk>  occurs when the rash becomes very widespread, and can develop from any of the other types. Fingernails and toenails are affected in most people with<unk>  at some point in time. This may include pits in the nails or changes in nail color.<unk>  is generally thought to be a genetic disease that is triggered by environmental factors. If one twin has<unk> , the other twin is three times more likely to be affected if the twins are identical than if they are nonidentical. This suggests that genetic factors predispose to<unk> . Symptoms often worsen during winter and with certain medications, such as beta blockers or NSAIDs. Infections and<unk> ychological stress can also play a role. The underlying mechanism involves the immune system reacting to skin cells. Diagnosis is typically based on the signs and symptoms. There is no known cure for<unk> , but various treatments can help control the symptoms. These treatments include steroid creams, vitamin D3 cream, ultraviolet light, and immunosuppressive drugs, such as methotrexate. About 75% of skin involvement improves with creams alone. The disease affects 2–4% of the population. Men and women are affected with equal frequency. The disease may begin at any age, but typically starts in adulthood.<unk>  is associated with an increased risk of<unk> oriatic arthritis, lymphomas, cardiovascular disease, Crohn's disease, and depression.<unk> oriatic arthritis affects up to 30% of individuals with<unk> . The word<unk> " is from Greek ψωρίασις, meaning "itching condition" or "being itchy" from<unk> ora, "itch", and -iasis, "action, condition".
Psoriasis
Onychomycosis
Parapsoriasis
Basal-cell carcinoma
Lupus vulgaris
Dermatitis
Vitiligo
Dandruff