Folliculitis

📌 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.