Etiology

Tricophytosis is due to a vegetable parasite, and is propagated from one to another by contact. Ringworm of the head is usually contracted by the careless habit among children of wearing each other's headgear, and in public institutions by the common use of brushes and combs, towels, etc. In nursing infants the trouble is sometimes conveyed to the breasts of their mothers.

Ringworm of the beard is perhaps more frequently contracted at barber shops than elsewhere, from the use of contaminated utensils, and may be passed in turn to the lips or cheeks of young women.

Tricophytosis is met in the rat, cat, dog, cow, horse, and perhaps in other animals, and may be conveyed by them to man. Cavalrymen, who are accustomed to practice their exercises on bare-back horses, sometimes contract the genito-femoral variety.