Here is a copy of my response to a question about psoriasis from another board.

Q: Could you please give me some suggestions for herbs that are good for psoriasis. My father has diabetes and high blood pressure, but also quite bad psoriasis, which is effecting his confidence dramatically. He is on conventional drugs for both conditions but is not taking anything for his psoriasis. Any suggestions will be much appreciated.

A: Psoriasis is not caused by infection or acidic blood as some people have claimed. Psoriasis is an imbalance between two chemical messengers in the body known as cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). The dominant messenger should be cAMP, but in psoriasis cGMP becomes dominant. This leads to the psoriasis as cGMP elevates PGE2, which is found in elevated levels in psoriatic skin cells. Arachidonic acid (AA) levels are also elevated with psoriasis. The primary source of AA is from meats in our diet. So reducing intake of red meats would also be a good idea.

A few suggestions are coleus forskohlii, nettle leaf or watercress, and fish and flax seed oils. Forskohlii, nettle leaf and watercress can all be used to elevate cAMP or help prevent its breakdown. The oils are sources of essential fatty acids that help counter AA.