1006 patients with typical and atypical lesions of atopic dermatitis (AD) were analysed statistically. The clinical severity was closely correlated to serum IgE values and RAST (radio-allergosorbent test) positivity. The frequency of RAST-positive antigens was significantly correlated with serum IgE values (gamma = 0.712; p < 0.01). The analysis of multiple correlation between the clinical severity and each RAST score for mite, egg white and rice antigens suggested a strong contribution of rice allergy to the development of severe AD. 25 patients with severe AD and positive rice-RAST were treated by rice exclusion diet. The results were as follows: 9 cases remarkably responsive, 10 cases moderately responsive and 6 cases unresponsive. The rice-RAST titre decreased most remarkably in the 1st group. The wheat-RAST titre also decreased in the 1st, in spite of taking wheat foods every day, but increased in the 3rd. A probable role of rice allergy in severe AD in Japan is discussed.