Abstract: Objective To find out the normal syndrome elements and symptoms of psoriasis vulgaris by using latent structure theory. Methods The symptoms of psoriasis vulgaris patients were collected by a uniform form, psoriasis vulgaris database was established and the data were copied into the database. The data were analyzed by constructing a Psoriasis Vulgaris latent structure model, and the results were explained by professional knowledge of Chinese Medicine. Results The latent structure model of psoriasis vulgaris had 43 latent variables and 111 latent categories. By using the Chinese medicine theory, it was concluded that the syndrome-elements of location of psoriasis vulgaris were: blood, liver, kidney, and spleen; the syndrome-elements of nature of disease of psoriasis vulgaris were: heat of blood, blood stasis, blood deficiency, dry because of blood deficiency, yang deficiency, qi deficiency, yin deficiency, dampness and heat. Conclusion The research used latent structure to analyze the data by no supervising, found latent structure is similar to the Chinese medicine theory. It is more objective and is a good way to do the syndrome standard research work. The research gave some support to establish standard for syndrome diagnosis of psoriasis vulgaris.

Key words: latent structure, psoriasis vulgaris, syndrome-element