Dr. Greene, our little son has had a horrible rash for three months and it is getting worse. He has seen 5 doctors, including 3 dermatologists, and we've lost track of the number of unhelpful prescriptions. They say it's severe psoriasis. Please help us get him relief. His fingers are bloody and raw. People cringe when they see him.

The first step toward successful treatment of any rash is to correctly identify it. Any child with a chronic or recurrent rash that is unresponsive to prescribed treatment deserves a trip to a pediatric dermatologist. With psoriasis, most kids have seen several doctors, even dermatologists, before the diagnosis is confirmed. Psoriasis is often not even considered in children because the average age of onset is 28 years; however, almost 40% of psoriasis patients actually develop the rash before age 20 (Dermatology Clinics, 1998; 16:593-608). Also, at least five different patterns of the psoriasis rash exist, all of which look quite different, adding to the likelihood of a missed diagnosis.

With psoriasis, getting the correct diagnosis is just the beginning of the problem. Psoriasis has long been a frustrating condition with disappointingly ineffective treatments. Right now, at the dawn of the 21st century, history is changing. Exciting new discoveries are tumbling out of many creative labs. Dramatic, safe, and effective treatments are just now becoming available.

So sound a trumpet! If you know someone with psoriasis that is not clearing up, he or she needs to contact a psoriasis center or an expert in psoriasis immediately. Helpful options now abound. More are right on the horizon.

According to the National Psoriasis Foundation, about 125 million people throughout the world suffer from psoriasis. The American Academy of Dermatology estimates that about 150,000 new cases are identified each year in the United States. Five recognized forms of psoriasis exist: (1) guttate, in which the skin looks as if a hot liquid has splattered on it; (2) plaque, the most common, with raised red patches and silvery scales; (3) inverse, in which the rash is mostly on flexion creases, such as the inside of the elbows; (4) erythrodermic, with sheets of reddened, scalded-appearing skin; and (5) pustular, with multiple little pimples. One or more of these forms can appear simultaneously in a person with psoriasis, and the disease can shift from one form to another.

Although psoriasis is a long-term, recurrent problem for most who have it, the extent of the problem varies from quite mild to quite debilitating. It might be only a mild scalp condition, easily controlled with the appropriate, over-the-counter shampoo. It might show up as temporomandibular joint disease (TMJ), geographic tongue, or pitted nails. Or, for 10-30%, it might include the swollen hands and feet of psoriatic arthritis. Each year, about 400 people in the United States die from complications of psoriasis (Drug Discovery Today, 1999; 4:222-231). And every year, between $1.6 billion and $3.2 billion is spent on psoriasis in the United States alone (Annals of Reported Medicine and Chemistry, 1997; 32:201-210). Much of this fortune is wasted on treatments that are ineffective or dangerous.

Growing understanding about what causes psoriasis is leading to more targeted and effective treatments.

I remember learning in high school physics that some experiments into the nature of light suggested that light is an energy wave, and others, that light is a particle. We now know that in some respects, both are true.