Folliculitis

Folliculitis is an inflammatory and infectious disorder of the hair follicle most commonly caused by bacterial infection, particularly Staphylococcus aureus. It represents a spectrum of disease ranging from superficial follicular inflammation to deep destructive infection (furuncle and carbuncle).

The condition occurs when microorganisms invade the hair follicle following occlusion, friction, maceration, shaving, or immunosuppression.

Etiology (Causes)

Infectious Causes

Non-infectious Causes

• Shaving (pseudo-folliculitis barbae)

• Occlusive clothing

• Oils, cosmetics

• Topical steroids

• Diabetes mellitus

• Obesity

• Hyperhidrosis

• HIV/AIDS

• Prolonged antibiotic use

• Friction (athletes, soldiers)

Pathophysiology

1. Disruption of follicular barrier

2. Microbial invasion of follicular ostium

3. Neutrophilic inflammation

4. Pus formation

5. Follicle rupture (deep disease)

6. Dermal necrosis and scarring

Progression:

Folliculitis → Furuncle → Carbuncle

Clinical Classification

Signs & Symptoms

Superficial Folliculitis

• Scattered follicular pustules

• Papules and erythema

• Mild itching

• Located on thighs, buttocks, beard, scalp, trunk

Deep Folliculitis / Furuncle

• Painful nodule

• Central pustule

• Necrotic plug discharge

• Surrounding cellulitis

Carbuncle

• Large fluctuant swelling

• Multiple drainage sinuses

• Fever

• Malaise

• Permanent scars

Chronic/Complicated

• Post-inflammatory hyperpigmentation

• Keloids

• Recurrent abscesses

Diagnostic Criteria

Diagnosis is clinical when the following are present:

• Follicle-centered pustules

• Erythematous papules

• Central hair shaft

• Pain or itching

• Possible pus discharge

• Systemic symptoms in severe disease

Investigations

Usually not necessary for mild disease, but indicated in recurrent/severe cases.

Differential Diagnosis

• Acne vulgaris

• Impetigo

• Hidradenitis suppurativa

• Scabies

• Insect bites

• Contact dermatitis

• Herpes simplex

• Cutaneous candidiasis

Treatment

Management depends on severity.

A. Non-Pharmacological Treatment

• Avoid irritants and friction

• Stop shaving temporarily

• Use electric clippers instead of razor

• Clean skin with soap and water

• Wear loose clothing

• Warm compresses 3–4 times daily

• Improve hygiene

• Weight reduction if obese

• Control diabetes

Pseudofolliculitis Barbae

• Stop shaving for several weeks

• Allow hair to grow ≥1 mm

• Avoid close shaving

B. Pharmacological Treatment

Local Therapy (Mild)

Potassium permanganate soaks 1:4000 for 15–20 minutes twice daily for 3–4 days

Apply one of the following:

• Gentian violet 0.5% every 12 hrs for 5 days

• Silver sulfadiazine cream twice daily

• Mupirocin 2% every 12 hrs for 5–7 days

• Fusidic acid 2% every 12 hrs for 5–7 days

Oral Antibiotics (Moderate/Severe)

Indications:

• Fever

• Extensive lesions

• Carbuncle

• Recurrent disease

• Immunocompromised patient

Options:

• Flucloxacillin

• Cephalexin

• Amoxicillin-clavulanate

• Clindamycin (MRSA risk)

Duration: 7–14 days

Incision & Drainage

Required for:

• Furuncle

• Carbuncle

• Abscess

Antibiotics alone are insufficient if pus present.

Complications

• Abscess formation

• Carbuncle

• Cellulitis

• Sepsis (rare)

• Scarring alopecia

• Keloids

• Hyperpigmentation

• Chronic recurrent furunculosis

Prevention

• Maintain good hygiene

• Avoid sharing towels and razors

• Proper shaving technique

• Keep skin dry

• Avoid tight clothing

• Control diabetes

• Treat nasal Staphylococcus carriers

• Avoid contaminated pools/hot tubs

• Early treatment of minor lesions

Prognosis