Causes of Ringworm :

Ringworm is a manifestation of a genus of fungus known as Trichophyton . The most common species related to ringworm in humans is Trichophyton rubrum . It is spread most commonly through infected household pets, but since it is a contagious infection, it can be spread through other infected individuals. Spread by humans does not require skin-to-skin contact; infection can be spread via combs, brushes, caps, pillowcases, worn clothes, and other inanimate objects that have come in contact with an infected person.

Trichophyton can be present on any region of the body. Zoopores generally cause infection in the neck, face, and arms. Anthrospores usually affect occluded areas of the skin or areas of trauma.

Trichophyton grows at a moderately rapid rate. Grown in pure culture, the texture of the colonies is waxy, glabrous to cottony. The colors of the colonies vary from opaque, yellow, white, brown, to red. Trichophyton is naturally found in animals, humans, and soil.