[Clinical study of scabies. The changes in the modes of transmission, and its diagnosis and treatment]

Scabies has become a common disease, not sexually transmitted but transmitted in households. Although it is also known to cause an epidemic in hospitals for the aged patients or residential homes, no effective treatment was taken for it at the present time. From January 1985 to December 1992, 424 patients with scabies (249 males and 175 females) visited the Dermatological clinic of Nippon Medical School Main Hospital. In these cases, only 13 patients (3.1%) were recognized as having STD. The sources of infestation were unclear in most cases where the disease was transmitted in households, which account for 38.5% of the patients. In 68 cases (16.0%), outbreaks of scabies in hospitals and residential homes affected the patients as well as the staffs and their families. The number of scabies cases which were infested in hospitals is increasing yearly. It is speculated that the hospitals for the aged patients and residential homes are becoming the main source of scabietic infestation. Only 16.6% of the patients were previously diagnosed or suspected to have scabies by their family doctors. It seems that the diagnosis of scabies is extremely difficult for the general practitioner. A considerable number of the patients who had been diagnosed or suspected to have scabies changed their doctor or stop visiting them. This is because an appropriate treatment is not available in most of medical facilities. At the time of the first visit to our clinic, 93.6% of the patients was diagnosed or suspected to have scabies, and the mite was demonstrated in 63.2% of the patients. It is suggested that careful inspection of scabietic burrows and the skillful technique to demonstrate the mite are essential to establish the diagnosis of scabies. Atopic dermatitis was the most common diagnosis of the patients who were misdiagnosed at the first time and later turned out to have scabies. These patients did have atopic dermatitis besides scabies. After the treatment with benzyl benzoate with crotamiton, 70.3% of the patients were cured and up to 94.9% of the patients were over improved. We compared the therapeutic effect of phenothrin to that of benzyl benzoate. Benzyl benzoate had more antipruritic effect and a little more improvement of skin lesion than phenothrin. However, there was no significant difference between benzyl benzoate and phenothrin in the period of time until the skin lesion cleared. Phenothrin is considered to have an adequate therapeutic effect for scabies.