Psoriasis

Up to 2% of Americans suffer from psoriasis, a skin condition that leads to an intensely itchy rash with clearly defined borders and scales that resemble silvery mica. The fingernails are also frequently involved, showing pitting or thickening.
Medical treatment for psoriasis includes applications of topical steroids and peeling agents that expose the underlying skin for the steroid to contact. Ultraviolet light can also be used, sometimes combined with coal tar applications or medications called psoralens. Synthetic versions of vitamin A can also be helpful. For especially problematic psoriasis, low doses of the anticancer drug methotrexate have proven quite effective.

Proposed Treatments for Psoriasis:

Fish Oil

There is some evidence that eicosapentaenoic acid (EPA) from fish oil may be a bit helpful in psoriasis. One 8-week double-blind study followed 28 people with chronic psoriasis. Half received 1.8 g of EPA daily (supplied by 10 capsules of fish oil), and the other half received placebo. By the end of the study, researchers saw significant improvement in itching, redness, and scaling, but not in the size of the psoriasis patches.

However, another double-blind study followed 145 people with moderate to severe psoriasis for 4 months and found no benefit as compared to placebo.

For more information, including dosage and safety issues, see the full fish oil article.

Oregon Grape

Preliminary evidence suggests that the herb Oregon grape (Mahonia) may help reduce symptoms of psoriasis, although it does not seem to be as effective as standard medications.

A double-blind placebo-controlled study involving 82 people with psoriasis tested the effectiveness of topical application of Mahonia. Participants used a placebo ointment on one side of their bodies and Mahonia on the other. According to the participants assessments, the Mahonia ointment produced significantly better results. However, the physicians did not observe significant differences between the two. One possible design flaw was that the treatment salve was darker in color than the placebo, possibly allowing participants to guess which was which.

Another study found that dithranol, a conventional drug used to treat psoriasis symptoms, was more effective than Mahonia. Regrettably, the authors fail to state whether this study was double-blind. Forty-nine participants applied one treatment to their left side and the other to their right for 4 weeks. Skin biopsies were then analyzed and compared with samples taken at the beginning of the study. The physicians evaluating changes in skin tissue were unaware which treatments had been used on the samples. Greater improvements were seen in the dithranol group.

A large open study in which 443 participants with psoriasis used Mahonia topically for 12 weeks found the herb to be helpful for 73.7% of the group. Without a placebo group, its not possible to know whether Mahonia was truly responsible for the improvement seen, but the trial does help to establish the herbs safety and tolerability.

Laboratory research suggests Mahonia has some effects at the cellular level that might be helpful in psoriasis, such as slowing the rate of abnormal cell growth and reducing inflammation.

For more information, including dosage and safety issues, see the full Oregon grape article.

Aloe

Aloe veracream may be helpful for psoriasis, according to a double-blind study that enrolled 60 men and women with mild to moderate symptoms of psoriasis. Participants were treated with either topical Aloe vera extract (0.5%) or a placebo cream, applied 3 times daily for 4 weeks. Aloe treatment produced significantly better results than placebo, and these results were said to endure for almost a year after treatment was stopped. The study authors also reported a high level of complete "cure," but what exactly they meant by this was not reported clearly.

Other Herbs and Supplements

Based on very preliminary evidence, shark cartilage has been proposed as a treatment for psoriasis.

Beta-carotene, burdock, chromium, Coleus forskohlii,goldenseal, topical licorice cream, milk thistle, red clover, selenium, taurine, vitamin E, and zinc are also sometimes mentioned as possible treatments for psoriasis. However, as yet there is no real evidence that they work.

A somewhat toxic natural substance called fumaric acid is sometimes recommended for psoriasis as well. Vitamin A or special forms of vitamin D taken at high levels may improve symptoms, but these are dangerous treatments that should be used only under the supervision of a physician.