Diagnosis

Folliculitis

Etiology

Cause [qm6]

• Usually caused by Staphylococcus aureus.

• Other causes:

  • Gram-negative: Enterobacter, Klebsiella, Escherichia, Serratia, Proteus, Pseudomonas

  • Virus: Varicella-zoster

  • Fungus: Tinea, Pityrosporum (Malassezia furfur)

  • Noninfectious: Trauma, occlusion

Pathophysiology [qm6]

1. Infection of the hair follicle

2. Result of inflammation secondary to ingrown hairs

3. Caused by certain drugs such as lithium and cyclosporine

Risk factors [qm6]

• Immune deficiency

• Anemia

• Diabetes

• Iron deficiency

• Poor hygiene

• Long-term antibiotic therapy (gram-negative)

Complications [qm6]

• Cellulitis

• Abscess

Epidemiology

Incidence per 100.000 [yrt][yap]

Prevalence per 100.000 [yrt][yap]

Approach

• Inspection (clinical diagnosis)

• Gram stain

• Culture

• Biopsi

Treatment

1. Superficial bacterial folliculitis: [yap][qm6]

   • Usually self-limited and will resolve spontaneously

   • Skin hygiene: Antibacterial ointment (Mupirocin) three times daily for 10 days

2. In recurrent, treatment-resistant, or deep bacterial folliculitis [yap][qm6]

   • First generation cephalosporins, penicillinase-resistant penicillin, macrolides and oral clindamycin may be used based on the results of the culture

   • If the culture does not reveal any organisms, tetracycline or doxycycline is preferred for their anti-inflammatory properties

   • If not self-limiting nature or manifests with constitutional symptoms, an oral third generation cephalosporin or fluoroquinolone may be beneficial

3. Pityrosporum Folliculitis: oral antifungal agents (Itraconazole and fluconazole)

4. Viral folliculitis: oral acyclovir, valacyclovir, and famciclovir

5. Demodex Folliculitis: anti-parasitic agents (topical permethrin 5% cream or oral ivermectin and oral metronidazole)

6. Eosinophilic folliculitis:

   • Antiretroviral therapy to treat the patient’s underlying HIV.

   • Optional therapies: topical corticosteroids, antihistamines, phototherapy, and even itraconazole or isotretinoin

Differential diagnoses

Acne, Acneiform eruptions, Acne keloidalis nuchae, Candidiasis, Coccidioidomycosis, Drug eruptions, Eczema, Erythema toxicum neonatorum, Fox-Fordyce disease, Furunculosis, Graham-Little-Piccardi-Lasseur syndrome, Hidradenitis suppurativa, HIV, Impetigo, Insect Bite, Keratosis pilaris, Milia, Miliaria, Molluscum contagiosum, Perioral dermatitis, Rosacea, Scabies, Seabathers eruption, Subcorneal pustular dermatosis, Urticaria