Autoimmune disease. A disease caused by a malfunction of the body's immune system, the natural defense system against infections. The immune system mistakenly attacks the body's own cells -- which can cause an autoimmune disease like psoriasis.
Biologic drugs / therapies. Medications made from living organisms to treat moderate to severe psoriasis. Biologic drugs work by targeting the harmful attacks from the immune system that cause psoriasis symptoms. Biologic drugs include Enbrel, Humira, Stelara, and Remicade.
Erythrodermic psoriasis. A serious type of psoriasis that affects most of the body. It appears as red skin with significant shedding of the skin associated with itching, pain, and change in body temperature. This usually requires hospitalization. It is the least common type of psoriasis.
Guttate psoriasis. The second most common type of psoriasis, primarily found on children and young adults. The skin spots are much smaller and not as thick as those of plaque psoriasis. They usually appear on the trunk, arms, and legs. They often occur suddenly with a cold or other respiratory infection, or after an episode of tonsillitis or a strep infection.
Immune system. The body's natural defense system which helps fight infections. When the immune system mistakenly attacks the body's own cells, it is called an autoimmune response -- which can trigger an autoimmune disease like psoriasis.
Inverse psoriasis. A type of psoriasis found in skin fold areas such as the armpit, groin and beneath breasts and buttocks. It appears as shiny, smooth red skin lesions.
Phototherapy. A treatment for psoriasis that involves brief exposures to ultraviolet light -- ultraviolet B (UVB) or A (UVA).
Plaque. Patches of scaling skin that cover sores, the symptoms of psoriasis. Plaque patches usually appear on elbows, knees, and trunk.
Plaque psoriasis. The most common type of psoriasis. Eighty percent of people with psoriasis have plaque psoriasis. It appears as raised, inflamed, red patches with silvery, white, or red scaly skin most often seen on the elbows, knees, lower back, and scalp.
Psoralen and UVA light therapy (PUVA). A treatment for psoriasis that involves taking psoralen medication before a brief exposure to ultraviolet A (UVA) light.
Psoriatic arthritis. A form of arthritis that may develop in someone with psoriasis. The fingers and toes are most often affected. People with pustular psoriasis or psoriasis involvement of the nails are more likely to develop psoriatic arthritis. Ten percent to 30% of people with psoriasis develop psoriatic arthritis.
Pustular psoriasis. A type of psoriasis characterized by the appearance of non-infectious, pus-filled pimples encompassed by red skin. It can be intensely painful, and hospitalization may be required.
Topical medications. Ointments, creams, and solutions that are applied to skin. Topical medications used for psoriasis include vitamin D, corticosteroids, retinoids, anthralin, and coal tar.