Folliculitis is inflammation of the hair follicles, most commonly due to infection by S. aureus but may be caused by other agents or mechanisms.
Pathophysiology
Folliculitis may be caused by:
Bacteria
- ⭐️ Most commonly S. aureus
- Gram-negative species - this occurs when a patient has a history of long-term antibiotics for acne
- Klebsiella
- Enterobacter
- Proteus
Fungi
- Malasseza folliculitis
- Candida spp.
- Trichophyton spp. - most commonly as tinea barbae.
Virus
- HSV - herpetic foliculitis.
There are other causes such as
- Eosiniphilic folliculitis - an autoimmune cause of folliculitis.
- Chemical irritation
- Physical irritation
⚠️ Risk factors
- Uncut beard
- Shaving against the grain
- Tight-fitting clothing
- Sweating and hyperhidrosis
- Skin abrasion
- Occluded skin
- Topical corticosteroids
- Immunosuppressed
😷 Presentation
It can be either superficial folliculitis (also known as impetigo of Bockhart) or deep folliculitis (sycosis)
- Red lumps on the skin - usually on hairy areas such as the axilla, beard, face, scalp, thighs and inguinal regions. It may also have a central pustule.
- Scarring - this is the biggest concern with deep folliculitis.
It is usually pain-free but it can cause itching and irritation.
🔍 Investigations
Clinical diagnosis based on appearance.
Swabs may be used for cultures in severe cases.
🧰 Management
Conservative management by avoiding tight-fitting clothing and high humidity, avoiding shaving, good hygiene. Mild-superficial folliculitis resolves without treatment generally.
Antibiotic treatment
- Topical fusidic acid - may be used with recurrent folliculitis.
- Flucloxacillin or erythromycin - may be used orally for deeper folliculitis.
- Topical clotrimazole - may be used for fungal folliculitis.
- Isotretinoin - may be used with gram-negative folliculitis.
- Aciclovir - for herpetic folliculitis.