[Investigation of mites in the houses of atopic dermatitis (AD) patients, and clinical improvements by mite elimination].

Seasonal variations related to mites were investigated by the Methylene Blue Agar (MBA) method in the houses of 157 AD patients living in Tokyo. Many mites were counted in the dust from carpets, Japanese straw mats (Tatami) and the floor under Tatami. In most places, the number of mites was found to increase in summer. In winter, however, mite levels increased in sofas and Japanese seat cushions. On the other hand, only small numbers of mites were found in mite-proof products. Based on the above data, were recommended mite elimination by various scientific techniques was recommended for 34 severe AD patients. Mite levels and clinical symptoms were again checked after one year and two years in the same seasons. In 17 of the 34 cases, mite elimination was carried out completely. In these cases, the ratio of mite decrease to less than 30% was 82%, and the ratio of improvement of clinical symptoms (remarkable improvement + improvement) was 88%. Almost complete cure was noted in 7 cases. On the other hand, in the remaining 17 cases, mite elimination was performed incompletely in 12 cases, and was hardly done at all in 5 cases. The ratio of mite decrease to less than 30% was 47%, and the ratio of improvement of clinical symptoms was 35%. Therefore, it was concluded that investigation of mite levels following mite elimination procedures is a most recommendable treatment for severe AD patients who are hypersensitive to house dust mites.