San Diego Psoriasis (and Psoriatic Arthritis) Treatment
Psoriasis is a recurrent or persistent, and usually chronic inflammatory condition of the skin. Psoriasis is common and occurs at a rate of nearly 2% of the United States population. The rash of psoriasis is usually asymptomatic, although some individuals with psoriasis may experience itching.
What causes psoriasis?
While the exact cause of psoriasis has not been determined, it is known that in psoriasis, a certain cell of the immune system called the T cell becomes over-activated to produce mediators of inflammation. Signals also are released which cause the skin cells to proliferate rapidly. Normally, skin cells are replaced every 30 days, the acceleration in the cell cycle results in replacement of skin cells every 3-4 days. There is a strong genetic component to psoriasis. Individuals with a strong family history of the condition are more likely to develop psoriasis.
A “trigger” is usually needed to make psoriasis appear in predisposed individuals. Psoriasis triggers include:
- Infection (e.g. strep throat, viral upper respiratory infections)
- Medications (beta blockers, lithium, antimalarial medications, interferon, indomethacin, others)
- Abrupt withdrawal of systemic or topical corticosteroids.
- Dry winter weather and lack of sunlight.
- Trauma such as cuts or scrapes to the skin can cause psoriasis to develop at the site of injury (known as Koebner`s phenomenon)
- Smoking and heavy drinking in certain individuals.
Types of psoriasis
There are five major types of psoriasis, each with unique signs and symptoms:
- Plaque psoriasis: The most common form of psoriasis, it accounts for 80% of cases. Patients develop raised red patches of skin with silver-white scale most commonly over the elbows, knees, scalp and lower back.
- Guttate psoriasis: “Guttate” refers to having the appearance of a raindrop. This form of psoriasis which appears as small red spots with whitish scaly spots usually affects children and young adults, most frequently following a strep throat infection. The rash usually spontaneously clears within several weeks.
- Pustular psoriasis: Characterized by white pustules surrounded by inflamed skin. This form of psoriasis is typically limited to the palms and/or soles. Generalized pustular psoriasis, however, can be a severe, life-threatening illness.
- Inverse psoriasis: Red, non-scaly plaques form in the skin folds including the underarms, beneath the breasts, in the groin, buttocks and genitals.
- Erythrodermic psoriasis: Full-body redness and inflammation of the skin with severe itching. Secondary infections and life-threatening complications including heart failure, respiratory problems may occur.
Approximately 25% of people who develop psoriasis develop psoriatic arthritis which causes inflammation, pain and deterioration of the joints. Psoriatic arthritis may occur in the absence of psoriasis. Early intervention is important to prevent permanent deformities and disability.
- Retinoids (e.g. tazarotene)
- Calcineurin inhibitors (e.g. tacrolimus, pimecrolimus)
Ultraviolet Light Therapy
Several forms of UV light treatment are useful for the treatment of psoriasis and especially useful for widespread disease. The effects of UV light on the skin are complex, but one effect is a decrease in the turnover rate of skin cells. A series of ultraviolet light treatments may result in a short- or long-term remission of psoriasis. The forms of UV light treatment administered by dermatologists is much safer than natural sunlight or the light obtained at tanning booths.
- Corticosteroids: generally should NOT be used due to the risk of a rebound effect, or worsening of psoriasis once the medication is discontinued.
- Methotrexate: useful for psoriasis and psoriatic arthritis, but not appropriate for individuals with liver or severe kidney disease.
- Cyclosporine: appropriate for short courses to control severe disease, blood pressure and kidney function must be monitored.
- Retinoids: e.g. acitretin. NOT appropriate for use in women of child-bearing age because of risk of severe birth defects.
- Biologic agents: e.g. etanercept, adalimimab, efalizumab, alefacept and infliximab. These agents may be excellent options for individuals who have failed other treatments.