Folliculitis – Causes, Symptoms, Diagnosis, Treatment and Ongoing care
- Inflammation of hair follicle caused by infection, chemical irritation, or physical injury
- Divided into superficial and deep folliculitis
- Eosinophilic pustular folliculitis (EPF), also known as Ofuji disease, is a distinct entity with sterile papules or pustules.
- Folliculitis decalvans is a rare inflammatory scalp disorder of middle-aged adults, with diagnostic overlap with perifolliculitis capitis abscedens et suffodiens.
- System(s) affected: Skin/Exocrine
- Predominant age: All ages
- Predominant sex: Male > Female
Pruritic folliculitis of pregnancy is a rare disorder that resolves spontaneously after delivery.
- Frequent shaving
- Pre-existing dermatoses
- Occlusive dressing
- Occlusive clothing
- Long-term antibiotic use
- Use of hot tubs or saunas
- Diabetes mellitus
- Close contacts with individuals with methicillin-resistant Staphylococcus aureus (MRSA) infections
- As an occasional complication of therapeutic epilation with intense pulsed light
- Practice good personal hygiene; avoid reinfection from contaminated clothing and washcloths.
- Minimize friction from clothing.
- Avoid shaving.
Predisposing factors to folliculitis:
- Nasal carriage of Staphylococcus aureus
- Exposure to pools and hot tubs contaminated with Pseudomonas aeruginosa(may be due to inadequate chlorination)
- Candida folliculitis related to recent antibiotic or corticosteroid use
- Staphylococcal infection
- Pityrosporum folliculitis may mimic acne.
- Demodex mite infection on the face and scalp
- Malassezia may cause folliculitis of the scalp.
- Herpes simplex is an uncommon cause.
- Herpes zoster may cause an area of folliculitis in an unusual location.
- As a reaction to cutaneous larva migrans infestation
- Pseudofolliculitis barbae may mimic true folliculitis.
- MRSA due to increasing incidence of community-acquired infections
- Pseudomonal folliculitis commonly erupts quickly after soaking in an infected spa or hot tub.
- Transplant patients taking sirolimus are at risk for scalp folliculitis.
- Eosinophilic folliculitis is uncommon in completely healthy adults, being more common in immunosuppressed patients, but in Japan it occurs as Ofuji disease.
Commonly Associated Conditions
- External otitis
- Pustular rash occurring on hair-bearing skin, especially the face (beard), proximal limbs, and scalp
- Pseudomonal folliculitis appears as a widespread rash mainly on the trunk and limbs when the growing hair curls around and penetrates the skin, provoking a foreign-body reaction.
- Gram-negative folliculitis occurs from long-term antibiotic therapy.
- Pityrosporum folliculitis occurs more often in warm, humid climates and more frequently in immunocompromised patients.
- Herpes folliculitis occurs from infection with herpes 1 and 2.
- Characteristic lesions are multiple small papules and pustules, usually measuring ≤5 mm in diameter with erythematous base pierced by a central hair.
- In pseudofolliculitis barbae, curled beard hairs with chisel-like tip may turn around and penetrate into the skin.
Diagnostic Tests & Interpretation
Initial lab tests
- Gram stain
- Potassium hydroxide preparation to look for budding yeast or hyphae
- Fasting blood sugar
- HIV status
Incision and drainage is rarely used because the scar formation may be ugly; disorder may return.
- Superficial/deep: Moderately intense infiltrate of inflammatory cells
- Pseudofolliculitis: Perifollicular inflammatory infiltrate
- Eosinophilic folliculitis: Collection of eosinophils within superficial follicle
- Acne vulgaris
- Acneiform eruptions
- Cutaneous candidiasis
- Contact dermatitis
- Papular urticaria
- Insect bite
- Systemic antibiotics do not appear to be helpful.
- Staphylococcal folliculitis:
- Mupirocin applied 2–5 times per day is drug of choice; oral agents are reserved for widespread disease.
- Dicloxacillin: 250 mg q.i.d. p.o. for 14 days
- Cephalosporin (Cephalexin): 250 mg q.i.d. or 1,000 mg b.i.d. for 10 days
- For MRSA:
- Clindamycin 150–450 mg p.o. q6–8h for 10 days
- Bactrim DS 1 b.i.d. for 10 days
- Minocycline or doxycycline 100 mg p.o. b.i.d. for 10 days
- Pseudomonal folliculitis:
- Usually self-limited; no antibiotic indicated
- If severe or persistent, adults can use ciprofloxacin 500 mg or ofloxacin 400 mg b.i.d. p.o. for 10 days
- Topical corticosteroids
- Itraconazole or fluconazole
- Topical tacrolimus ointment
- UVB light
- Herpetic folliculitis:
- Valacyclovir 500 b.i.d. for 5 days
- Famciclovir 125 mg b.i.d. for 5 days
- Acyclovir 800 b.i.d. for 5 days
- Recurrent disease:
- Vitamin C (1 g/d × 4–6 weeks)
- Mupirocin nasal ointment (5 days)
- Low-dose clindamycin (150 mg/d × 3 months)
- Antibacterial soaps (Dial, Chlorhexidine)
- Good handwashing techniques
- Warm compresses
- Clean shaving instruments each day.
- Change towels/washcloths and sheets daily.
- Avoid nose picking.
- For obese individuals, weight reduction may be helpful.
Issues for Referral
Incision and drainage is rarely used because the scar formation may be ugly, and disorder may return.
- Resistant cases should be followed every 2 weeks until cleared.
- 1 return visit in 2 weeks if symptoms abate
For obese individuals, weight reduction may be helpful.
Avoid shaving in involved areas.
- Usually resolves with treatment
- May recur in Staphylococcus carriers
- Mupirocin may be required on nares of patient to treat carrier state.
- Family carriers may also require treatment.
- Resistant or severe cases may warrant testing for diabetes mellitus or immunodeficiency.
- Primary complication of concern is recurrent folliculitis
- May progress to become furuncles or abscesses
1. Böer A, Herder N, Winter K, et al. Herpes folliculitis: clinical, histopathological, and molecular pathologic observations. Br J Dermatol.2006;154:743–6.
2. Ellis E, et al. Eosinophilic pustular folliculitis: a comprehensive review of treatment options. Am J Dermatol. 2004;5(93):189–97.
3. Sladden MJ, et al. More common skin infections in children. Br Med J.2005;330(7501):1194–8.
See Also (Topic, Algorithm, Electronic Media Element)
Algorithm: Rash, Focal
704.8 Other specified diseases of hair and hair follicles
13600006 Folliculitis (disorder)
- Folliculitis is a pyoderma localized to hair follicles.
- The lesions of folliculitis measure ≤5 mm in size, are erythematous, pruritic, and usually cluster in groups.
- Systemic antibiotics do not appear to be helpful in treating folliculitis.
- Consider MRSA in difficult-to-treat cases.