What is the treatment for an infected hair follicle?

Treatment for Infected Hair Follicle

The primary treatment for an infected hair follicle (folliculitis) depends on severity - small furuncles can be treated with warm compresses, while larger furuncles and all carbuncles require incision and drainage, with systemic antibiotics reserved for cases with surrounding cellulitis, fever, or immunocompromised patients. 1

Types of Infected Hair Follicles

Infected hair follicles present in several forms:

• Folliculitis: Superficial inflammation of the hair follicle with pus limited to the epidermis
• Furuncle (boil): Deeper infection extending through dermis into subcutaneous tissue, forming a small abscess
• Carbuncle: Multiple adjacent infected follicles forming a coalescent inflammatory mass with multiple drainage points

Treatment Algorithm

1. For Mild Folliculitis

• Warm compresses: Apply several times daily to promote drainage and healing 1
• Topical antibiotics: Mupirocin or retapamulin for localized lesions 1
• Topical antiseptics: Chlorhexidine washes can help prevent spread 1

2. For Furuncles (Boils)

• Small furuncles: Warm compresses to promote spontaneous drainage 1
• Larger furuncles: Incision and drainage is the recommended treatment (strong evidence) 1
• Post-drainage care: Simply covering the surgical site with a dry dressing is usually most effective; packing may cause unnecessary pain 1

3. For Carbuncles

• Incision and drainage is mandatory for all carbuncles (strong evidence) 1
• Culture of drainage material is recommended to guide antibiotic therapy if needed 1

4. Systemic Antibiotics - When to Use

Systemic antibiotics should be added when:

• Extensive surrounding cellulitis is present
• Systemic symptoms are present (fever, tachycardia, tachypnea, abnormal WBC) 1
• Patient has markedly impaired host defenses
• Multiple lesions are present
• In outbreaks affecting several people 1

5. Choice of Antibiotics

• For methicillin-susceptible S. aureus: Penicillinase-resistant penicillins (e.g., dicloxacillin) or first-generation cephalosporins 1
• For suspected MRSA: Trimethoprim-sulfamethoxazole, doxycycline, or clindamycin 1
• Duration: 5-10 days for most cases 1

Management of Recurrent Folliculitis/Furuncles

For patients with recurrent episodes:

1. Decolonization regimen: 5-day course of intranasal mupirocin twice daily 1
2. Daily chlorhexidine washes 1
3. Decontamination of personal items: Towels, sheets, and clothes 1
4. For nasal carriers: Application of mupirocin ointment twice daily in the anterior nares for the first 5 days each month reduces recurrences by ~50% 1
5. For severe recurrent cases: Consider clindamycin 150 mg daily for 3 months, which decreases subsequent infections by ~80% 1

Special Considerations

• Immunocompromised patients should receive systemic antibiotics even for mild cases 1
• Diabetic patients are at higher risk for carbuncles, particularly on the back of the neck 1
• Evaluate for underlying causes in recurrent cases (e.g., neutrophil disorders if recurrent abscesses began in early childhood) 1
• Avoid unnecessary packing of drained abscesses as this may cause more pain without improving healing 1

Common Pitfalls to Avoid

1. Misdiagnosing bacterial abscess: Kerion (inflammatory fungal infection) can mimic bacterial folliculitis 1
2. Overuse of antibiotics: Not all folliculitis requires systemic antibiotics 1
3. Inadequate drainage: Needle aspiration is not recommended for abscesses (successful in only 25% of cases) 1
4. Missing systemic disease: Recurrent folliculitis may indicate underlying immunodeficiency 1
5. Neglecting decolonization: For recurrent cases, addressing bacterial colonization is essential 1

By following this treatment algorithm based on the severity of the infected hair follicle, most cases can be successfully managed with appropriate local care and selective use of antibiotics.