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 psoriasis, 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. Psoriasis is associated with an increased risk of psoriatic arthritis, lymphomas, cardiovascular disease, Crohns disease, and depression. Psoriatic arthritis affects up to 30% of individuals with psoriasis.The word "psoriasis" is from Greek ψωρίασις, meaning "itching condition" or "being itchy" from psora, "itch", and -iasis, "action, condition". Signs and symptoms
Plaque psoriasis
Psoriasis vulgaris (also known as chronic stationary psoriasis or plaque-like psoriasis) is the most common form and affects 85–90% of people with psoriasis. Plaque psoriasis typically appears as raised areas of inflamed skin covered with silvery-white, scaly skin. These areas are called plaques and are most commonly found on the elbows, knees, scalp, and back. Other forms
Additional types of psoriasis comprise about 10% of cases. They include pustular, inverse, napkin, guttate, oral, and seborrheic-like forms. Pustular psoriasis
Pustular psoriasis appears as raised bumps filled with noninfectious pus (pustules). The skin under and surrounding the pustules is red and tender. Pustular psoriasis can either be localized or more widespread throughout the body.
Macrognathism is an abnormally large or protruding jaw. The opposite condition is called micrognathia. Causes
Heredity
Pituitary gigantism
Pagets disease of bone
Acromegaly
Fetal alcohol syndrome
Leontiasis ossea
Cleidocranial dysplasia

Treatment
Treatment is surgical. Osteotomy may be done in case of maxillary macrognathia. Mandibular macrognathia is generally managed by resection of a portion of the mandible. == References ==