Psoriasis is a recurrent disorder in which patches of skin become red and covered by dry, silvery scales. About 5 million Americans have the condition, which usually develops during young adulthood through late middle age. Although psoriasis is seldom serious medically, the unsightly lesions can lead to emotional problems. Normally, the skin is in a constant state of renewal, with new cells forming in the dermis, or inner layer, and pushing upward into the epidermis, which sheds the old, dead cells. With psoriasis, the skin makes new cells so fast that they form silvery scales. Then, new blood vessels are created to nourish these immature cells, resulting in the typical reddening of the skin. The initial patches typically form on the scalp, behind the ears, on the back of the neck, between the shoulders, and on elbows and knees or near fingernails and toenails. Some patients also develop psoriatic arthritis, a potentially crippling joint disorder that resembles rheumatoid arthritis. In unusual cases, the entire body is covered with red, scaly patches, a variation called exfoliate psoriasis. Another form, pustular psoriasis, is characterized by blisters, usually on the palms and soles. The cause of psoriasis is unknown, but it is thought to be an autoimmune disorder, perhaps with an inherited predisposition. The condition tends to wax and wane, with symptoms often disappearing for months or even years at a time. Recurrences can be triggered by a severe sunburn, a reaction to a medication, an injury, or stress.

Diagnostic Studies And Procedures

Diagnosis is usually made by inspecting the skin for the typical layers of dry, silvery scales, but a skin biopsy may be ordered in some cases. If joints are painful and inflamed, X-rays and blood studies will be done. The absence of rheumatoid factor in the blood serum distinguishes psoriatic arthritis from rheumatoid arthritis.

Medical Treatments

If only small patches of skin are affected, self treatment or application of a prescription strength corticosteroid ointment may be effective. Calcipotriene (Dovonex), a topical drug derived from vitamin D, appears promising in slowing the growth of new skin cells. Severe cases can benefit from photo chemotherapy, a treatment in which the skin is exposed to ultraviolet A light rays following administration of psoralen, an oral medication that enhances the healing potential of the light. This approach is known as PUVA, an acronym for psoralen plus ultraviolet A. Very severe conditions may be treated with anticancer drugs, such as methotrexate, which slow the production of new cells. Etretinate (Tegison), an anti psoriatic drug, or isotretinoin (Accutane), a derivative of vitamin A used to treat severe cystic acne, are effective against pustular psoriasis.

Alternative Therapies

Herbal Medicine

Herbalists and naturopaths recommend applications of a mixture of lavender and olive oils, or bergamot and comfrey oils, to the scaly patches. Yarrow oil added to bath water is also said to help reduce scaling. A combination of the tinctures of burdock, sarsaparilla, and cleavers in equal parts, taken in doses of 1 teaspoon three times a day, may also be helpful.

Hydrotherapy

Warm compresses applied to affected skin for several minutes each day may be soothing. Some people with severe psoriasis have traveled to the Dead Sea area in Israel for special water and sun treatment. Sun bathing in this locale is beneficial because of its unique geography, 1,300 feet below sea level. At this altitude, the concentration of ultraviolet A light rays is higher than anywhere else on earth. Salt and mud mixtures from this region are also sold as treatments for psoriasis.

Meditation

Because stress is known to provoke psoriasis, this and other relaxation techniques can be preventive.

Nutrition Therapy

Although it has not been proved that psoriasis is related to food allergies or sensitivities, some people appear to benefit from dietary changes. To identify possible offenders, eliminate a food or group of foods for a few weeks to see if there is any improvement. Then return the food to the diet; if it produces a flare up, it may well playa role in triggering psoriasis. High doses of vitamin D have been found effective for treating psoriasis. Because this approach is still experimental, patients should not attempt to treat themselves with it.

Self Treatment

Mild cases often can be controlled with diligent self care that includes regular use of lubricants such as white petrolatum or a vegetable shortening. Using an oatmeal soap and adding a cup of sea salt to bath water may also help. If scaling persists, nonprescription cortisone cream or coal tar ointments, creams, or shampoos, such as Pentrax lotion, P&S Plus gel, or Sebutone cream or solution, can be tried. Their use should be checked beforehand with a dermatologist, but a typical regimen calls for applying the cream or lotion at night, covering it with plastic wrap, washing it off in the morning, and then exposing the skin to the sun or artificial ultraviolet light. Thick scalp plaques can be treated with overnight applications of a solution of mineral oil and 10 percent salicylic acid. To enhance the effectiveness and keep the preparation off bedding, wear a shower cap to bed, Judicious exposure to the sun often helps, but care is needed because too much sun can worsen psoriasis.

Other Causes of Skin Scaling

Seborrheic dermatitis (dandruf, can cause scalp scaling, though the lesions are usually greasy and yellow. Other conditions that should be ruled out include squamous cell skin cancer, dermatitis, fungal infections, eczema, and lichen planus, a recurrent itchy rash.