What is psoriasis? Why did it take so long for my son to be diagnosed?

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 (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.

The five recognized forms of psoriasis include:

• Guttate, in which the skin looks as if a hot liquid has splattered on it.
• Plaque, the most common, with raised red patches and silvery scales.
• Inverse, in which the rash is mostly on flexion creases, such as the inside of the elbows.
• Erythrodermic, with sheets of reddened, scalded-appearing skin.
• 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 5% to 10%, it might include the swollen hands and feet of psoriatic arthritis.