Folliculitis is a skin condition or group of skin conditions in which there is inflammation in the hair follicles. This causes a somewhat painful red bump at the affected hair follicle, and a small pustule can form. This can occur anywhere on the body that has hair: scalp, chest, back, arms, legs, and buttocks. Sometimes there may just be one occasional affected hair follicle, other times there may be many hundred. This can look a lot like some forms of acne, and some severe forms of acne are associated with folliculitis on the body.
Folliculitis may be caused by blockage of sweat ducts associated with a hair follicle, by bacteria, by fungus, by herpes family viruses, by demodex or scabies mites, by irritation from ingrown hairs, by corticosteroids or other medications, or by immunosuppression. Bacterial folliculitis is most often due to Staphylococcus aureus, but “hot tub folliculitis” is caused by Pseudomonas aeruginosa, and “Gram negative folliculitis” may appear after treatment with a tetracycline antibiotic.
Your dermatologist will ask numerous questions about recent illnesses, recent medications, other skin conditions or chronic medical conditions, and recent exposures to help identify the cause of folliculitis. Sometimes a culture of a pustule or a skin biopsy may aid in the diagnosis. Medication may be prescribed to clear the rash, which varies according to the causative agent. If a medication is causing the problem, this must be stopped, and a different medication may be prescribed. If the irritation is from regrowing/ingrown hairs, it is advised to stop shaving, waxing, electrolysis, or plucking if one of these is the cause, and to not try hair removal again for at least 3 months after the rash has resolved. Several acne variants may cause forms of this skin condition, and treatment may include topical acne treatment as well as an oral tetracycline antibiotic, isotretinoin, or anti-androgen medication (in women). For chronic back folliculitis, traditional treatments may be unsuccessful. In this case, permanent hair removal may be best for long term treatment.