Etiology of ringworm of the scalp, beard and body in Rome, Italy.

From 1972 to 1977 the authors examined 1,311 patients in Rome affected by ringworm of the scalp, beard and body, comparing their findings with a study made in Milan between 1969 to 1973 and with earlier Italian studies from 1900 to date. It appears that at the beginning of the century scalp ringworm was usually caused by Trichophyton violaceum and T. tonsurans, whereas Microsporum canis was rarely found. Today the Trichophyton species are rarely isolated, whereas Microsporum species, particularly M. canis (88.9% of the cases in Rome, 74.6% in Milan), predominate in the etiology of scalp ringworm. Ringworm of the beard in Rome is mainly caused by T. mentagrophytes (50% of the cases) and T. verrucosum (25%). In Milan the frequency of T. verrucosum is 51.2% and of T. mentagrophytes 38.5%. Ringworm of the body today is mainly due to M. canis (47.8% of the cases in Rome and 65.7% of those in Milan). These ringworms in Rome and Milan are caused mostly by the zoophilic dermatophytes that have supplanted the anthropophilic dermatophytes, which were the main cause of dermatomycoses in the early years of this century. This change, particularly evident after World War II, appears to result from improved socio-economic and hygienic conditions, with resulting decrease of infections through interhuman contacts, and from increased numbers of pet animals and consequent increase of stray cats and dogs, which result in increase of infections of animal origin.