A bacterial infection and irritation of the hair follicle is termed folliculitis.

Folliculitis is probably the most common of all skin infections. Although usually trivial, it can produce extensive disease. It may be superficial or deep, and it causes the formation of a pustule or inflammatory nodule surrounding the hair. The infected hairs may be easily removed.

A more extensive folliculitis of the sebaceous gland (the oily secreting glands) with some involvement of subcutaneous tissues is...