II. Pathophysiology
- Usually caused by Bacterial Infection
- Superficial inflammation of Hair Follicle
- Only upper Hair Follicle involved
- Contrast with Deep Folliculitis
III. Risk Factors
- Local Trauma
- Abrasion
- Surgical wounds or draining abscess
- Shaving
- Aggravates Staphylococcus aureus Folliculitis
- Exposure to Occlusive Dressing
- Tar
- Adhesive plaster
- Plastic Occlusive Dressings
IV. Causes
- See Folliculitis
- Staphylococcal Folliculitis (most common)
- Affects beard area (Folliculitis barbae)
- Also affects axillae and legs
- Aggravated by shaving
- Pseudomonas Folliculitis (Hot Tub Folliculitis)
- Pseudofolliculitis Barbae
- Eosinophilic Folliculitis (HIV)
-
Superficial Fungal Infection
- Malassezia Folliculitis
- Dermatophyte Folliculitis
- Candida Folliculitis
- Viral Folliculitis
- Herpetic Folliculitis
- Molluscum Folliculitis
- Drug-Induced-Folliculitis
- Steroid Folliculitis (corticoseroids)
- Phenytoin
- Lithium
- Isoniazid
- Cyclosporine
- Epidermal Growth Factor Receptor Inhibitors or EGFR Inhibitors (e.g. Erbitux, Vectibix, Tarceva, Iressa, Tykerb)
V. Symptoms
- Non-tender or minimally tender
- Variably pruritic
VI. Signs
- Characteristics
- Pustule confined to Hair Follicle
- Hair Shaft may be seen at center of lesion
- Yellow or gray coloration with erythema
- Distribution: Any skin bearing hair
- Head and neck
- Trunk
- Buttocks
- Extremities
- Absent features
- No associated fever or systemic symptoms
VII. Differential Diagnosis
- Acne Vulgaris
- Acne Keloidalis Nuchae
- Papulopustular Rosacea
- Keratosis Pilaris (younger patients)
- Hidradenitis Suppurativa
-
Cutaneous Candidiasis (Candida albicans)
- Seen in febrile hospitalized patients
- Beard area Folliculitis
- See Beard Dermatitis
- Trunk Folliculitis
- Tinea Corporis (Ringworm)
- Pustular Miliaria
- Not perifollicular
- Occurs in hot, humid weather
VIII. Labs (As Indicated)
- Pustule Gram Stain and Culture
- KOH Preparation
- Fungal Culture
- Skin Biopsy
- Nasal MRSA Swab
IX. Management
-
General
- Eliminate provocative agents (tar, Mineral Oil)
- Keep affected areas clean and dry
- Avoid occlusive clothing and excessive sweating
- Consider warm, wet Burow's Solution
- Consider Topical Corticosteroids for significant associated inflammation
- Approach to infection management
- Staphylococcal Folliculitis is most common, but is not the only Folliculitis cause (see causes above)
- Consider Pseudomonas Folliculitis (Hot Tub Folliculitis)
- Consider Gram Negative Folliculitis
- Consider fungal Folliculitis (dermatophyte Folliculitis, candida Folliculitis)
- Staphylococcal Folliculitis
- Topical Antibiotics
- Apply Mupirocin ointment three times daily to affected areas for 7 to 10 days or
- Topical Clindamycin (Cleocin-T) twice daily for 7 to 10 days
- Systemic Antibiotics (refractory to topical agents)
- Avoid Macrolides due to increased resistance
- Dicloxacillin 250 to 500 mg orally four times daily for 7 to 10 days or
- Cephalexin (Keflex) 250 to 500 mg orally four times daily for 7 to 10 days or
- Cefadroxil (Duricef) 500 mg orally twice daily for 7 to 10 days or
- Doxycycline 100 mg orally twice daily for 7 to 10 days (MRSA coverage) or
- Trimethoprim-Sulfamethoxazole (Septra, Bactrim) orally twice daily for 7 to 10 days (MRSA coverage)
- Prevention (Suppression of infection)
- Daily washing with antimicrobial skin cleanser (e.g. Benzoyl Peroxide)
- Topical Clindamycin (Cleocin T) after shaving
- Mupirocin (Bactroban) in nostrils
- Topical Antibiotics
X. Course
- Heals without scarring
XI. References
- Jackson in Rosen (2022) UpToDate, Accessed online 8/8/2022
- Fitzpatrick (1992) Color Atlas Dermatology
- Habif (1996) Dermatology, p. 248-51
- Stulberg (2002) Am Fam Physician 66(1):119-24 [PubMed]