Psoriasis is a congenital skin condition.
It is a chronic skin disease in which scaly pink patches form on the elbows, knees, scalp, and other parts of the body. It is one of the commonest skin diseases in Britain, affecting about 2% of the population (cause unknown). It often runs in families, the commonest time of onset being in adolesence.
Psoriasis sometimes occurs in association with arthritis. Sometimes psoriasis can be very severe, affecting much of the skin and causing considerable inconvenience and disability to the sufferer.
While psychological stress can make psoriasis worse, the only significant event thought to precipitate this condition is a preceeding streptococcal infection.