Psoriasis is a chronic disease of the immune system that has symptoms
ranging from scaly red patches appearing on this skin, to pitting and
deformation of nails, to inflammation of joints. Any part of the body
can be affected by psoriasis. As many as 7.5 million Americans have
psoriasis, according to the National Institutes of Health. There are
five types of psoriasis: plaque, guttate, inverse, pustular, and
erythrodermic. Currently there is no cure for psoriasis, but there are
treatment options available.