What is folliculits ? how does it happen?

Skin infection: Folliculitis is an infection of a hair follicle ( hence the name). Any hair bearing skin can be affected. It is most common on the face, neck and groin. Anything that irritates the hair follicle can cause this. Makeup, work related chemicals, tight fitting clothes that rub the skin, and sweat are often involved in blocking the follicles. Bacterial infection follows the irritation.

Possibly infection: Folliculitis is an infalmmation of the hair follicle. This could be as a result of either irritation like shaving too closely or could be a true bacterial infection of the hair follicle.