Table of Contents
Overview
Folliculitis is a common superficial infection or inflammation of hair follicles. It can affect any hair-bearing area and is frequently encountered in general practice and dermatology clinics. Most cases are benign and self-limiting, but persistent or widespread lesions may require antimicrobial therapy. It’s important to distinguish it from deeper infections such as furuncles and carbuncles.
Definition
A pustular infection or inflammation of one or more hair follicles.
Aetiology
- Bacterial:
- Staphylococcus aureus (most common)
- Pseudomonas aeruginosa (e.g. hot-tub folliculitis)
- Fungal:
- Malassezia spp. (yeast)
- Dermatophytes
- Viral:
- Herpes simplex virus (rare)
- Mechanical or irritative:
- Shaving, waxing, friction, occlusion
- Other factors:
- Immunosuppression
- Diabetes mellitus
- Long-term corticosteroid use
Pathophysiology
- Follicular disruption (by trauma, occlusion, or shaving) → entry of microbes
- Localised inflammatory response in and around hair follicle
- Results in papules, pustules, and erythema centred on follicles
Clinical Features
- Erythematous pustules centred around hair follicles
- May be tender or itchy
- Usually localised but may be widespread in immunocompromised individuals
- Common sites:
- Scalp, beard area
- Chest and back
- Groin and buttocks
- Legs (especially after waxing or shaving)
2. Da pacem Domine, CC0, via Wikimedia Commons
Variants of Folliculitis
| Type | Cause | Notes |
|---|---|---|
| Bacterial | Staph aureus | Most common |
| Hot-tub | Pseudomonas aeruginosa | Often self-limiting |
| Pityrosporum | Malassezia furfur (yeast) | Often affects trunk in young adults |
| Gram-negative | Often after prolonged antibiotic use | May affect acne patients |
| Viral | HSV | Rare |
Differential Diagnoses
- Acne vulgaris
- Furunculosis / carbuncles
- Keratosis pilaris
- Contact dermatitis
- Fungal infections
Management
General Measures
- Improve hygiene
- Avoid shaving over affected areas
- Use clean/new razors and avoid occlusive clothing
- Avoid hot tubs and shared towels during outbreaks
Topical Therapies
- Antiseptics (e.g. chlorhexidine wash)
- Topical antibiotics (e.g. mupirocin, clindamycin)
- Topical antifungals (e.g. ketoconazole) for fungal folliculitis
Systemic Therapy
- Oral antibiotics for extensive or recurrent bacterial folliculitis
- Flucloxacillin, cephalexin
- Oral antifungals (e.g. itraconazole) for resistant fungal cases
Complications
- Furuncle/carbuncle formation
- Scarring or post-inflammatory hyperpigmentation
- Recurrence
Summary
Folliculitis is a superficial infection or inflammation of hair follicles, most often due to Staph aureus. It presents as erythematous pustules centred on hair follicles, commonly after shaving or waxing. Management involves hygiene optimisation and topical or systemic antimicrobials based on the underlying cause. See the Skin & Dermatology section for related notes.