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What Is Psoriasis?
Psoriasis is a genetically programmed inflammatory disease that affects primarily the skin in about 3% of individuals in the United States. Psoriasis begins as a small scaling papule. When multiple papules coalesce, they form scaling plaques. These plaques tend to occur in the scalp, elbows, and knees.
Symptoms of Psoriasis
Although psoriatic plaques can be limited to only a few small areas, the condition can involve widespread areas of skin anywhere on the body. These plaques can be itchy, and when the scale is peeled away, small bleeding points may appear. Psoriasis tends to occur in areas of trauma. This condition often waxes and wanes spontaneously.
Many patients with psoriasis have abnormal nails. Psoriatic nails often have a horizontal white or yellow margin at the tip of the nail called distal onycholysis because the nail is lifted away from the skin. There can often be small pits in the nail plate, and the nail is often yellow and crumbly.
Psoriasis can be associated with a destructive arthritis called psoriatic arthritis. Damage can be serious enough to permanently damage the affected joints. Prevention of joint damage in such cases is very important.
What Causes Psoriasis?
It is now clear that there is a genetic basis for psoriasis. This hereditary predisposition is necessary before the disease can be triggered by environmental factors. White blood cells called T-cells mediate the development of the psoriatic plaques that we seen in the skin.
The environmental factors that seem to trigger psoriasis include:
- streptococcal sore throat,
- trauma to the skin,
- certain drugs,
- alcohol in excess.
The Stigma of Psoriasis
There is plenty of evidence that extensive psoriasis can have a very significant negative effect on a patient’s self-image and emotions. This is especially true in social situations, although all aspects of life can be disturbed. Inverse psoriasis, which affects the genital skin, and scalp psoriasis can be particularly troubling. Psoriasis affecting the hands may make it impossible to interact normally with others.
Psoriasis is often diagnosed by a competent physician or at least suspected on the basis of its appearance and distribution. Occasionally it may be necessary to remove a small piece of skin (a biopsy) and have it examined by a pathologist to confirm this conviction. If there are joint symptoms, X-rays and other laboratory tests may be in order. Psoriasis cannot be cured, but like many other medical conditions, it is controllable with treatment.
Psoriasis Treatment: Topicals
Since psoriasis mainly affects the skin, topical treatments are very useful because they are relatively safe, quite effective, and can be applied directly to the disease. They take the form of lotions, foams, creams, ointments, gels, and shampoos. They include topical steroids, tar preparations, and calcium- modulating drugs. The precise drug used and the form in which it is delivered depends on the areas involved. In widespread disease in patients with more than 10% of the body surface involved, it may not be practical to use topical medication. treatments.
Psoriasis Treatment: Phototherapy
For more extensive disease, a useful option is ultraviolet light exposure. Ultraviolet light (UVL) exposure can treat large areas of skin with few side effects if performed in the physician’s office. It should be kept in mind that all UVL causes mutational events, which can lead to skin cancer. At this time, the most popular type of UVL for psoriasis is called narrow-band UVB. Only a small portion of the UVL spectrum is used, which seems to be particularly beneficial for psoriasis and may of less carcinogenic potential. This UVB is quite different from the UVA, the wavelength available in tanning salons.
Psoriasis Treatment: Laser Therapy
There are lasers that produce UVL in wavelengths similar to narrow-band UVB. These can be quite effective for small plaques of psoriasis, but because the areas of skin that can be treated at one time are small, they are not practical for extensive disease.
Psoriasis Treatment: Oral Medications
There are a variety of drugs administered systemically that are useful in controlling psoriasis. The choice of which drug to use depends upon many factors which make this a very individual choice. Since these drugs are administered either orally or through the skin, they are more risky for the patient than topical medications. As a generalization, most seem to act by targeting portions of the immune system. The only exception currently is a drug called acitretin (Soriatane), which is structurally similar to vitamin A. Since the immune system is necessary in order to survive, systemic treatments do have a downside. Drugs like methotrexate and cyclosporine are administered orally and can affect the liver, kidney, and bone marrow.
Psoriasis Treatment: Biologics
A new class of drugs has recently been developed called biologics; they're called biologics because living cells synthesize them. Since these drugs are proteins, they cannot be administered orally and must be given by injection through the skin or by an intravenous infusion. These drugs are very precise in their target and block a single step in the immune process. This seems to have increased their safety profile when compared to older drugs. On the other hand, they are quite expensive.
Natural Remedies for Psoriasis
Since the natural solar spectrum contains ultraviolet light, there is no question that heliotherapy (medicinal sunbathing) can be effective in controlling psoriasis. There is mounting evidence that increased body mass is associated with psoriasis and that heavier individuals are more difficult to treat. So a normal body mass is desirable. There is some dispute as to the role of diet in psoriasis, but a diet low in saturated fats is desirable for many reasons including weight control. So-called "natural or botanical" treatments have very little evidence to support their use.
At the edge of Israel's Dead Sea, there are a group of resorts that cater to psoriasis patients by offering a combination of graded solar exposure and the application of crude coal tar along with a spa-like experience. For those with the time and the money, this is a reasonable alternative to standard medical treatment.
Although there is no doubt that psoriasis is a potent inducer of stress, the evidence that stress causes psoriasis is sparse. Dealing with stress with or without psoriasis is a challenge for most people living in the 21st century.
The National Psoriasis Foundation is an excellent source of accurate information as well as emotional support for afflicted patients.
More Reading on Psoriasis