Goldenseal (Hydrastis canadensis) is another herb said to control psoriasis flare-ups. Its active components are the alkaloids hydrastine and berberine.

Unfortunately, the same substances can lead to digestive problems and other toxic symptoms. Common side effects of goldenseal are diarrhea, convulsions, abortion and hypertension.

"High doses may cause nausea, vomiting, a decrease in the white blood count and feelings of pins and needles in the hands and feet," according to Dr. Sheldon Saul Hendler in "The Doctors' Vitamin arid Mineral Encyclopedia."

Below are other quack cures for psoriasis that you should avoid:
Vitamins and minerals - Many people take vitamins in the mistaken belief that they will prevent and treat serious diseases. But the facts say otherwise: The only people who need vitamins are those suffering from vitamin deficiencies which are unlikely to occur if you eat a balanced diet, that is, a variety of foods everyday.

In spite of this, vitamin salesmen like to tell people that they need vitamins even if they don't. What they fail to tell their customers is that a vitamin deficiency is extremely rare except in severely malnourished individuals.

Psoriatic patients are not spared from all this nonsense. In their effort to get rid of the disease, they may fall prey to the unfounded claims of vitamin hucksters in the medical marketplace. One of the vitamins promoted for psoriasis is vitamin E which is said to help if taken orally or applied to the skin.

This myth is an extension of yet another false claim, namely, that vitamin E is good for the skin, can prevent scars and stop wrinkles from developing. None of this has been scientifically demonstrated.

"Vitamin E has no value when applied to the skin's surface or the hair. Vitamin E does not penetrate the skin's outer layers, and all of its claims for healing powers are without scientific foundation. In fact, there is evidence that when vitamin E is forced through the layers of the skin (as with spray-on preparations), it can cause severe allergic reactions," according to Deborah Chase in "The No-Nonsense Beauty Book."

"Claims of favorable effects on skin remain purely anecdotal. So do claims that vitamin E promotes healing of burns and cuts and minimizes scar tissue," added Hendler.

Vitamin E supplements are equally worthless for skin conditions like psoriasis. The problem with taking too much is that you can suffer from side effects like nausea, headache, increased blood clotting time, increased blood pressure, fatigue and muscle weakness. This can occur with daily doses of 600 international units (IUs) or more.

"The assumption that more vitamin E is likely to be better than less is a naive and dangerous one। Vitamin E has proved time and again just how complex and sometimes unpredictable it is," Hendler added. (Next: Niacin for psoriasis?)