The causes for psoriasis may be multi-factorial. However, most naturopathic physicians believe there is a strong connection between skin conditions and the digestive system. The "gold standard" for testing food sensitivities is called the elimination and rotation diet. A food is eliminated for at least 5-6 weeks, and symptoms are monitored. The food is reintroduced and symptoms are monitored. Most allergists will test food allergies with a "scratch test" whereby a small amount of the substance is scratched into the skin and the skin reaction is monitored. Your dermatologist may/may not provide this test. Blood tests are also available from a variety of laboratories. Food sensitivities (vs. allergies) may not produce a measurable reaction in blood tests, so other types of testing may be needed to identify sensitivities. Some psoriasis may also benefit from light therapy and certain supplements.
answered by Dr K B N