Folliculitis is a common infection that is defined as inflammation of the hair follicles. It can be due to infections (bacterial or fungal), inflammation, or blockage of the pores. Most cases are superficial. Deeper cases of folliculitis are harder to treat and may result in scarring. Diagnosis is clinical
- Common locations
- Beard area for adult men (pseudofolliculitis – sterile)
- Legs or arms in people who shave (pseudofolliculitis – sterile)
- Sweaty areas (groin or buttocks)
- Causative organisms
- Staphylococcus aureus (most common)
- Pseudomonas (hot tub folliculitis)
- Gram-negative bugs (associated with long-term antibiotic use, especially in acne)
- Risk factors for folliculitis
- Sports
- Uncut beard or shaving “against the grain.”
- Clothing friction
- Humid environment
- Sweating
- Use of topical steroids
- Immunosuppression
- Skin abrasion
- Carrier of Staphylococcus aureus in the nose
- Occluded skin
- Signs and symptoms
- Rash → pustules → furuncle → carbuncle
- Differentials
- Acne vulgaris
- Herpes simplex
- Keratosis pilaris
- Contact dermatitis
- Milia
- Periorificial dermatitis
- Insect bites
- Investigation
- Pus swab
- Punch biopsy if diagnosis is uncertain
- Workup for diabetes if there are recurrent episodes
- Treatment
- Personal hygiene + use of chlorhexidine body wash
- Topical antibiotics: mupirocin, clindamycin
- Systemic antibiotics: flucloxacillin, cephalexin
- Isotretinoin for gram-negative folliculitis
- Incision and drainage for deep infections
