Folliculitis Organism-Specific Therapy

Before a treatment plan is devised, it is important to consider the etiology of the folliculitis and the severity and distributions of the lesions.

Organism-specific therapeutic regimens for folliculitis are provided below, including those for Staphylococcus aureus, methicillin-resistant organisms, Pseudomonas aeruginosa, Klebsiella, Escherichia, Serratia marcescens, Proteus, Malassezia furfur, Trichophyton, herpes simplex virus, and eosinophilic pustular folliculitis.

Staphylococcus aureus:

Topical antiseptics:

• For patients in whom S aureus colonization is suspected, bleach baths or bleach soaks may be of benefit. ^{[1, 2]}  Briefly, for a full tub of water, use 1/2 cup of household nonconcentrated bleach, or, for a half-full tub, use 1/4 cup of bleach. Pour the bleach into the tub prior to entering, and soak in the tub for 5-10 minutes. Do not submerge the head, and be careful not to get water in the eyes. Wash off with clean water and pat dry.  This can be done 2-3 times a week.
• If bleach compresses are preferred, 1 teaspoon of bleach should be put in each gallon of water. Using a white wash cloth, soak the affected area for 5-10 minutes and follow with a clean-water rinse. If treating a focal area, this can be done once to twice daily for symptomatic relief.
• Alternatively, white vingear can be used instead of bleach, diluting 1 part vinegar to 4-6 parts water.
• Chlorhexidine, Phisoderm, or benzyl peroxide washes once to twice a day are also effective.
• Light noncomedogenic moisturizers can be applied after the above washes to prevent excessive dryness or irritation.

Topical antibiotics ^{[3, 4]} :

• Clindamycin or erythromycin lotion, solution, or gel applied BID to affected areas until lesions resolve or

• Bacitracin or mupirocin ointment applied BID to affected areas until lesions resolve

• Mupirocin ointment can also be applied to nasal vestibule BID for 5d to eliminate the S aureus carrier state ^[5]

Systemic antibiotics ^{[3, 4, 6, 7]} :

• Dicloxacillin 250 mg PO q6h for 7-10d or

• Cephalexin 250-500 mg q6h for 7-10d

Methicillin-resistant organisms:

If the infection is caused by a methicillin-resistant S aureus (MRSA) organism, then antibiotic selection should be based on sensitivity testing and includes clindamycin, trimethoprim-sulfamethoxazole, minocycline, doxycycline, or linezolid. More recently, daptomycin, tigecycline, telavancin ceftaroline, dalbavancin, oritavancin, and tedizolid phosphate all have gained FDA approval for treatment of skin and soft-tissue infections. ^{[7, 8, 9, 10, 11, 12, 13]}

• Clindamycin 300-450mg PO q6-8h for 10-14d; D-zone test should be performed to identify inducible clindamycin resistance or
• Minocycline 100 mg BID for 10-14d  or
• Doxycycline 100 mg BID for 7-10d  or
• Trimethoprim-sulfamethoxazole (160/800mg)  1 DS tablet BID for 7-14d  ^[14]

For severe deep infections not amendable to incision and drainage or for patients with infections resistant to the above antibiotics (methicillin-susceptible S aureus [MSSA]), consult with an infectious disease specialist and consider linezolid 600 mg q12h for 10-14d. However, use of this agent is limited owing to cost and toxicity.

Rifampin has excellent activity against MSRA and can be used in combination with one of the above agents. It should not be used as monotherapy owing to the rapid development of resistance to this agent.

Pseudomonas aeruginosa:

See the list below:

• Treatment is typically only need if the patient is immunocompromised or the lesions are persistent. The initial drug of choice is  ciprofloxacin 500 mg PO BID for 7-14d ^[15]

Other gram-negative folliculitis:

Klebsiella, Escherichia,Serratia marcescens, and Proteus:

• Trimethoprim-sulfamethoxazole (160 mg/800 mg) 1 DS tablet BID for 10-14d or

• Ampicillin 250-500 mg q6h for 10d or

• Isotretinoin 0.5-1 mg/kg/day for 4-5mo

Malassezia furfur:

Topical antifungals:

Topical therapies are most useful as adjunctive therapy with oral antifungals, as well as for maintenance and prophylactic therapy since often there is a tendency for recurrence.

• Ketoconazoleor selenium sulfide shampoos used as a body wash daily or

• Ciclopirox olamine suspension gently massaged into the affected and surrounding skin areas BID or

• Econazole cream or foaming solution applied BID for 2-3wk

Systemic antifungals:

• Fluconazole 100-200 mg/day for 3wk or

• Itraconazole 200 mg/day for 1-3wk

Demodex folliculorum:

Topical agents:

• 5%  permethrin, apply to affected area, leave on 8h, and wash off
• 1% ivermectin cream applied once a day has been approved for rosacea
• 10% sulfacetamide with and without 5% sulfur washes and creams applied daily
• Over-the-counter tea tree shampoos may also be beneficial ^[16]

Systemic agent:

Systemic therapy should only be used in symptomatic patients resistant to the above therapies and who have a biopsy-proven infection.

• Ivermectin 200 µg as a single dose

Trichophyton species

• Micronized griseofulvin 500-1000 mg/day for 4-6wk or

• Ultramicronized griseofulvin 500-700 mg/day for 4-6wk or

• Itraconazole 200 mg BID for 1wk monthly for 2 pulses or

• Terbinafine 250 mg/day for 2-3wk

Herpes simplex virus  ^[17]

• Acyclovir 200 mg 5 times daily for 5-10d ^{[18, 19]}  or

• Valacyclovir 500 mg TID for 5-10d or

• Famciclovir 500 mg TID for 5-10d

Eosinophilic pustular folliculitis:

This condition is not due to an infection; therefore, it does not respond to systemic antibiotics. ^{[20, 21, 22]}

Treatments used with variable success:

• Betamethasone valerate 0.1% applied BID for 3-24wk or

• Tacrolimus BID for 3-24wk or

• Isotretinoin 0.5 mg/kg/day for 4-8wk or

• Itraconazole 200-400 mg/day PO for 2-3wk or

• Metronidazole 250 mg PO TID for 4wk or

• Indomethacin 25-50 mg/day PO for 1-8wk or

• Broadband UV-B phototherapy 3 times weekly for 3-6wk or

• Cetirizine 20-40 mg PO BID as needed for pruritus

• Nonsteroidal anti-inflammatory agents such as ibuprofen 200 mg PO q6h for 1-8wk

Special considerations:

Most cases of folliculitis are diagnosed clinically, but cultures with sensitivities, Gram stain, potassium hydroxide (KOH), or biopsy can be obtained if lesions do not resolve with empiric therapy.

Nasal cultures should be performed if S aureus colonization is suspected. If infection/colonization persists despite appropriate therapy and treatment of household members, cultures from nonnasal sites (axillary, inguinal, and rectal) should be considered. ^[5]

Family members also may be nasal carriers of S aureus; recommend the use of mupirocin ointment applied to the nasal vestibule BID for 5d and/or rifampin 600 mg/day PO for 10d, which may eliminate the carrier state ^{[4, 19]}