📌 Folliculitis: Essentials
- Common skin condition seen in GP, dermatology, and infectious disease clinics.
- Appears as small red papules/pustules around hair follicles.
- Can occur on scalp, face, beard, trunk, buttocks, groin, or legs.
- Usually self-limiting, but persistent cases may need systemic therapy.
🦠 Aetiology
- 💉 Bacterial: Staphylococcus aureus (most common), MRSA in recurrent/healthcare settings.
- 💦 Pseudomonas (“hot tub folliculitis”): contaminated pools/jacuzzis.
- 🍞 Fungal: Malassezia (pityrosporum folliculitis), dermatophytes (tinea barbae).
- 🦠 Viral: HSV → peri-oral or genital folliculitis.
- 🧪 Other: Gram-negative folliculitis (long-term acne antibiotics), friction (shaving, tight clothing), topical steroids (“steroid acne”).
🔎 Clinical Features
- Red papules or pustules centred on follicles (1–5 mm).
- Pruritus, tenderness, or burning.
- Distribution: beard area (“barber’s itch”), trunk, buttocks, scalp.
- May crust, ooze, or form small abscesses.
- Recurrent or deep cases → scarring, alopecia, cellulitis.
🧪 Diagnosis
- 👀 Clinical exam: usually sufficient.
- 🧫 Swab & culture: recurrent or spreading infection → guides antibiotics.
- 🔬 KOH prep: if fungal cause suspected.
- 🧬 Biopsy: atypical/refractory cases (e.g., folliculitis decalvans, eosinophilic folliculitis in HIV).
📂 Subtypes
- 💉 Bacterial folliculitis: topical mupirocin/clindamycin → oral flucloxacillin if severe.
- 💦 Pseudomonas (hot tub): self-limiting; ciprofloxacin if severe/systemic.
- 🍞 Pityrosporum folliculitis: itchy papules on back/chest → topical ketoconazole, oral fluconazole if resistant.
- 🧪 Gram-negative folliculitis: acne patients on long-term antibiotics → consider isotretinoin.
- 🦠 Viral (HSV): grouped vesicles/pustules → aciclovir/valaciclovir.
💊 Management
- 🧼 General: hygiene, avoid occlusive clothing, change razors, antiseptic washes (chlorhexidine).
- 💊 Topical: mupirocin, clindamycin, benzoyl peroxide.
- 💉 Oral antibiotics: flucloxacillin or doxycycline if widespread.
- 🍞 Antifungals: topical ketoconazole or oral azoles for fungal folliculitis.
- 🦠 Antivirals: aciclovir for HSV-associated cases.
- ⚠️ Refractory/recurrent: screen for diabetes, HIV, immunosuppression; dermatology referral.
📌 Complications
- 🔴 Abscess formation.
- 🧑🦲 Scarring alopecia (esp. scalp folliculitis decalvans).
- 📉 Chronic recurrence in diabetes, immunosuppression, or atopic patients.
- 🦠 Cellulitis, septicaemia (rare).
💡 Teaching Pearl: Folliculitis is common and often benign, but persistent or unusual cases may unmask systemic conditions (e.g., diabetes, HIV, immunosuppression). Always think beyond the skin.