RINGWORM 



165 



skin in mice. Intravenous and intraperitoneal injections into rabbits 

 produce nodular lesions of the lungs or peritoneum respectively. 



Cases of favus contracted from lower animals are not nearly so 

 frequent as the purely human form. Of these the mouse type is more 

 frequently seen. It occurs on the smooth skin, rather than the scalp. 

 Multiple scutula may develop, but the disease does not tend to spread 

 and progress as in the infections with T. Schoenleini. The parasite 

 of mouse favus is T. quinckeanum. 



Ringworm. Ringworm is a parasitic infection of the skin due to 

 various fungi belonging in the genera Trichophyton and Micro- 



FiG. 82. Ringworm of the smooth skin. 



sporum. It occurs endemically in some centers of population and at 

 times produces small epidemics. The disease is transmissible from 

 man to man, from lower animals to man, and, rarely, from man to 

 animals.^ It was formerly a very common disease, especially in 

 children of the poorer classes. For a time in Paris special schools 

 were maintained for children with ringworm. Partly as a result of a 

 rapid means of treatment utilizing Roentgen rays, the disease has 

 greatly decreased in prevalence within recent years. 



The disease is transmitted by means of the spores formed in or 

 on the skin and hairs, either by direct contact or indirectly through 

 combs, brushes, or towels. It may be contracted from animals also 



