Psoriasis is a chronic skin disorder characterized by red, thick and scaly rashes that are most often found on the scalp, elbows, knees and lower back. It can affect people of all ages and has a tendency to run in families.
The exact cause of psoriasis is not fully understood but it is NOT contagious. The immune system is involved, which triggers the inflammation and rapid growth of localized areas of the skin. Environmental factors such as dry skin, a lack of sunlight, infections and certain medications (beta blockers, lithium, etc.) may activate psoriasis.
The severity and pattern of psoriasis varies from person to person. Most affected individuals have chronic plaque psoriasis that covers the skin in red patches, scales and plaques. It may only affect the scalp and be mistaken for dandruff (scalp psoriasis), or it may be so mild that people don’t even know they have it. In some, the body folds are affected (inverse psoriasis) while in others the entire skin surface may be affected resulting in generalized redness (erythrodermic psoriasis). The nails may also be affected in psoriasis, showing pits, thickening or loosening of the nail. Various joints may be affected in up to 30% of people with psoriasis, resulting in painful, swollen joints (arthritis) that can cause some disability in function.
