The cause is not known. Recent research reveals it is due to abnormality in the functioning of key white cells, leading to skin inflammation. The skin begins to shed every 2-3 days instead of the normal 4 weeks. Psoriasis can develop 1-2 weeks after an injury or sunburn. Sore throat or streptococcal infection can trigger or flare-up the disease.
The common form of psoriasis has red bumps with silvery scales on elbow, knee, back and scalp. The nail can get involved in the form of pitting nail, yellow nail or nail dystrophy.
Inverse psoriasis affects covered areas of the body like armpits, groin and flexural surfaces.
Treatment for Moderate-to-Severe Psoriasis
Ultraviolet B (UVB) Light
UVB is the treatment of choice for people with moderate psoriasis (defined as patients with psoriasis on 20 percent or more of their body) who have not responded to topical modalities of therapy. UVB, in combination with home moisturizing, benefits patients within 20 to 30 treatments, resulting in remission about 70 percent of the time.
PUVA (Psoralen plus Ultraviolet A)
PUVA therapy (initiated at Harvard University in 1974) utilizes a medication called psoralen which absorbs UVA light. This results in a decrease in the proliferation of epidermal cells.
Psoralen is taken orally, followed by a UVA light treatment 75 minutes later. Treatments are given two to three times per week, and an average of 20 treatments usually will clear the condition.
Although PUVA is extremely effective in treating moderate psoriasis, its relative risks require thorough evaluations prior to initiation of therapy.
Psoriasis of the Scalp
In many psoriatics, the condition exists solely on the scalp. Scalp psoriasis is often non-responsive to home therapies, which include tar shampoos and topical steroids. Treatment for scalp psoriasis may include a whirlpool scalp hydrobath which gently debrides and therapeutically shampoos the scalp. Nurses apply various tar lotions or anthralin before and after the hydrobath.
Psoriasis Day Care Treatment
Psoriasis day care treatment utilizes the Goeckerman regimen in an outpatient setting. This regimen requires four to six hours of treatment per day, utilizing medicated whirlpool baths, and topical agents (crude coal tar, anthralin, moisturizers) which are applied by nurses prior to and after Ultraviolet B light therapy. Patients are treated five to six times per week. Eighty percent of patients experience a remission of their condition following a three to four week course of therapy.
Psoriasis day care allows individualized treatment Monday through Saturday, AM or PM. This offers the patient the convenience of returning home and, in many cases, returning to work while continuing treatment. In addition to the convenience afforded the patient, the cost is usually 10% - 15% the cost of a hospital admission.
Topical Treatments for Mild Psoriasis
Of the two million people in the United States with psoriasis, about 75% are affected in localized areas at the elbows, knees, scalp, or a few areas on the body. Localized psoriasis often responds well to topical therapy. Various topical treatment alternatives are considered, including:
- Ointments, creams and emollients containing steroids, tars, and salicylic acid
- Anthralin
- Vitamin D derivatives containing Calcipitriol
- Intralesional cortisone injections
