Psoriasis

Psoriasis is a skin disorder affecting 2 or 3 people per hundred. Although it does not affect physical health it very unsightly and can have an enormous psychological impact. Psoriasis can occur at any age but typically appears in late childhood through to early middle age. Once psoriasis has appeared there is no ‘cure’ but it may disappear for long periods. It is not a progressive disease and is notoriously unpredictable.

Psoriasis typically appears as reddened, scaly and thickened areas of skin, particularly on the scalp, elbows and knees, although it may appear on hands, feet or the groin. The ‘plaques’ result from accelerated growth of the outer skin layer, and abnormalities of the skin protein, keratin. The plaques are often localised, and can affect finger and toenails. There appears to be a genetic predisposition to psoriasis although many cases occur without a family history. The exact cause of psoriasis is no known, but the immune system is known to be involved, and it can be triggered or aggravated by stress, minor injury or sunburn.

A small proportion of psoriasis sufferers have arthritis which appears to be associated. Psoriatic arthritis usually develops in people who have had psoriasis for many years. Psoriatic arthritis can affect any joint in the body, but typically affects the outer joints of the fingers and toes, and the lower spine.

Medical treatment of psoriasis

Treatment generally consists of topical creams, lotions and ointments

Topical treatments

(1) Tar. A traditional treatment that can be helpful for mild psoriasis. The mechanism is unknown. Tar ointments are often combined with anti-inflammatory steroid creams (2) and salicylic acid to remove scale. Over-the-counter tar preparations can help mild psoriasis.

(2) Topical steroids. Used particularly in itchy inflamed psoriasis. Long term use of any steroid is inadvisable. They can cause thinning of the skin and generally become ineffective with time.

(3) Daivonex (Calcipitriol). A derivative of Vitamin D that seems to be helpful in some cases. Skin irritation may be a side effect.

Dithranol cream is occasionally used to reduce psoriasis plaque where skin thickening is pronouned. It is not a treatment for psoriasis, simply a palliative measure treating one symptom.

Ultraviolet light

Many psoriasis sufferers improve with UV light exposure. This includes sunlight, sunbeds, home UVB machines and purpose-designed UV light machines. Both UVB and PUVA in combination with sensitising chemicals can be used. There is a risk of skin cancer with all UV treatments.

Drugs

These are effective but also have serious side effects. There are three main drugs used but none offer a permanent cure:

Acitretin (Neotigason). This is a retinoid derived from Vitamin A and related to the drug Roaccutane used in treating severe acne. It can be very effective in some cases. Side effects include dry skin and lips and sun sensitivity.

Cyclosporin. This is a powerful immune suppressing drug used in organ transplantation. It can be very effective in severe psoriasis but at the cost of crippling the immune system and opening the way for infection and possibly cancer. It has also been associated with high blood pressure and impaired kidney function.

Methotrexate. Used once weekly this can completely control severe psoriasis. It is particularly effective in cases where arthritis is associated. Methotrexate has been shown to cause liver damage and a periodic liver biopsy (a very unpleasant procedure) is usually recommended.

Given the treatments that are effective it seem most likely that psoriasis is yet another of the epidemic of ‘auto-immune’ diseases that have marked the last half century. As such it may be the functional outcome of damage inflicted at a cellular level by trans-fats and omega-3 deficiencies that characterise the ‘modern’ diet. There may be a viral trigger, but no specific candidate virus has yet been identified.

Supplementation with borage oil may help improve symptoms of psoriasis but cannot effect a cure. Supplement the diet with 2 to 3 grams of borage oil per day, with an equal quantity of flax oil and/or fish oil to ensure that the omega-3:omega-6 ratio does not become too imbalanced. In addition, apply the oil topically directly to affected areas. If the treatment is going to help, improvements in symptoms may be noted during the first three or four weeks and can continue for some time. Maintenance supplementation should continue indefinitely at a lower dosage of around a gram per day..

For psoriatic artthritis, a number of sufferers have reported that MSM is extremely helpful in doses of 400-500mg taken twice daily.