According to the National Institutes of Health, as many as 7.5 million Americans have psoriasis. In fact, it is such a big problem in this country that sufferers have a national association (the National Psoriasis Foundation) that, among other key activities, mobilizes an annual walk-a-thon. Recognizing their pain, Abbott Laboratories created Humira, the latest drug to battle this debilitating disease.

Contrary to misguided belief, psoriasis is not just some itchy scalp dandruff. Psoriasis is an immune disorder that affects the skin and joints. It is characterized by itchy, scaly, red patches of dead skin cells. Psoriasis can develop on any part of the body, including the genitals.

According to the National Psoriasis Foundation, there are five types of psoriasis: plaque, the most common form of the disease; guttate, appears as small red spots on the skin; inverse, occurs in armpits, groin and skin folds; pustular, white blisters surrounded by red skin; and erythrodermic (severest form): intense redness over large areas. In its most severe form, one can develop psoriasis arthritis, which causes pain and swelling around the joints.
Makers of Humira say that the drug can help halt further damage to joints in those with psoriasis arthritis.

How does it work? According to the National Psoriasis Foundation, Humira blocks tumor necrosis factor-alpha (TNFalpha), a chemical "messenger" in the immune system that signals other cells to cause inflammation. There is too much TNF-alpha in the skin of people with psoriasis and the joints of people with certain types of arthritis. Patients give themselves a shot of the drug every other week.

Unfortunately, Humira is not for everyone. Abbott Laboratories says the drug should not be used for people with: a history of heart failure, pregnancy, a series of infections, hepatitis B, nervous system diseases or children. Since the drug has been on the market, many with the disease are improving. In a 24-week study of psoriatic arthritis, patients on the drug, nearly one out of four patients (23 percent) achieved 70 percent improvement in arthritis severity scores, reports the National Psoriasis Foundation.

However, Humira is also not cheap. The medicine costs between $10,000-$25,000 a year. Some insurances provide partial or full coverage for those with a diagnosis of psoriatic or rheumatoid arthritis. However, Abbott Laboratories has a patient discount program for those who qualify.