An infection of the hair follicles. The most common bacteria causing this disorder is Staphylococcus aureus although other bacteria such as Streptococcus can be involved. The disorder can occur from irritation to the skin such as shaving (Barber's itch) or from exposure to bacteria in a hot tub (hot tub folliculitis). Most infections are minor and some will resolve on their own without specific treatment. At times the infection can spread and involve the surrounding skin (cellulitis). Typically the infection causes pain and itching and small white pimples are seen at the base of the hair follicle. The disease is more common in patients with a weakened immune system. Other causes include: obesity, diabetes, acne, or topical steroid use.