Clinical Reference / Therapeutic Strategies / Folliculitis (including pseudofolliculitis barbae)

Folliculitis (including pseudofolliculitis barbae)


Key Points

  • Folliculitis is a term that encompasses follicular-based inflamed papules or pustules that may stem from a wide variety of causes.
  • Important causes of folliculitis include infection (bacterial, yeast, and viral), friction, medication-induced, or folliculitis associated with pregnancy.
  • Because Staphylococcus aureus is a common cause of folliculitis, a bacterial culture is always indicated to determine whether methicillin-resistant Staphylococus aureus (MRSA) is present, as this determines appropriate antibiotic treatment.
  • Pseudofolliculitis barbae is a challenging condition in which a chronic folliculitis develops in hair-bearing areas. A combination of alternative epilation, topical corticosteroids, keratolytics, and laser hair removal (where available) is the first-line therapeutic strategy.

Introduction

Folliculitis

Folliculitis is commonly caused by penicillin-resistant strains of S. aureus. Gram-negative forms occur, usually on the face, in the setting of chronic, broad-spectrum antibiotic therapy of acne vulgaris. Since inflammation is limited to the hair follicle, classic signs of infection (dolor, calor, rubor, and tumor) may be absent, making differentiation from milaria, papulovesicular viral exanthems, and acneiform eruptions difficult. Folliculitis is a common presentation of infection with community-acquired methicillin-resistant Staphylococcus aureus. As such, follicle contents should be sampled for Gram stain and culture as an important diagnostic step to determine whether an infection with an antibiotic-resistant strain is present.

When evaluating patients with folliculitis, there are unique and unusual causes that should be considered in the differential diagnosis, including frictional, chemotherapy-related (specifically with epidermal growth factor receptor inhibitors), pregnancy-associated, and a broad spectrum of infectious causes. Infections causing folliculitis in addition to Gram-positive and Gram-negative bacteria include those caused by the Demodex mite, yeast (such as Pityrosporum), and viruses such as herpes simplex and molluscum contagiosum. A thorough review of systems, history/physical, and a biopsy with culture may be helpful to clarify the diagnosis.

Pseudofolliculitis Barbae (PFB)

Pseudofolliculitis barbae (PFB) or razor bumps is a condition commonly affecting black individuals, though it may present in hair-bearing areas of skin in persons of all races. PFB may be the most common dermatologic condition of African-Americans, with a prevalence as high as 45-83%. The pathophysiology is largely unknown. This condition likely stems from inward growth of tightly curled hair within the hair follicle, resulting in abscess formation or a foreign-body giant cell reaction in a follicle-based distribution. It is often exacerbated by shaving and/or waxing, and resolves when the inciting form of hair removal is stopped. There are several basic factors that make management challenging; first, no method of hair removal, especially shaving, works for all patients and, second, with time many patients learn the best hair removal technique for them, but often only after several to numerous unsuccessful attempts. Finally, many individuals with PFB cannot be continuously “clean shaven,” which may result in social isolation or interfere with certain forms of employment (which do not allow for facial hair). Severity of disease dictates therapeutic options. Laser epilation offers an important therapeutic option for individuals with PFB, when available. Addressing secondary pigmentary alteration and/or keloid formation may also be an important aspect of the therapeutic strategy.

Initial Evaluation

Folliculitis

Pseudofolliculitis barbae

Differential diagnosis

Acne

Majocchi’s granuloma

Atypical mycobacterium

Treatment

Folliculitis

First-line therapy: The first-line therapy for folliculitis includes the treatment of the appropriate cause, typically infection. A diagnostic biopsy or culture may be necessary to identify the inciting infectious cause.

  • For Gram-positive folliculitis: dicloxacillin 250 mg q.i.d., oral erythromycin (in penicillin-allergic individuals) 250 mg q.i.d., or cephalexin 500 mg t.i.d. for 10 days.
  • Alternate initial therapy for methicillin- or erythromycin-resistant strains: Trimethoprim-sulfamethoxazole (either Septra DS or Bactrim DS) 1 tablet b.i.d. or doxycycline hyclate 100 mg b.i.d. for 10 days.
  • Gram-negative folliculitis: A single course of isotretinoin usually is curative. A referral to a dermatologist should be considered.

Alternative steps

  • Instruct the patient to shower daily with either chlorhexidine (such as Hibiclens) or povidone-iodine (such as Betadine) washes. Close contacts of patients also should consider using antiseptic cleansers over the same time period to avoid transmittance within the family and/or recurrences.
  • The skin of the buttocks is particularly susceptible to recurrent episodes of folliculitis, primarily due to friction. The frequency of such episodes can be decreased with the wearing of loose-fitting cotton underwear, loose-fitting trousers, frequent applications of an astringent powder (such as Zeasorb) to shorts, and/or daily applications of an astringent solution (such as aluminum chloride or Xerac-AC).

Pitfalls

  • Consider the differential diagnosis of folliculitis: frictional, gram-negative bacterial, herpetic, or Pityrosporum folliculitis. Appropriate microbiologic cultures are indicated if the folliculitis is not responding to standard antibacterial therapy.
  • Relapses are common owing to persistent nasal carriage, transmission between family members, inadequate length of treatment, emergence of methicillin-resistant strains (recurrent lesions should be re-cultured), and rarely, an underlying immunologic abnormality. When relapses occur, a prolonged course of antibiotic therapy will result in permanent clearing in about 80% of patients.

Pseudofolliculitis barbae (PFB)

First-line therapy: The first-line therapy for PFB is to devise a strategy for alternative hair epilation, if possible. A combination of topical steroids and retinoids may be a helpful adjunctive therapy. Laser hair removal, when possible, is an important therapeutic consideration. Pigmentary alteration and keloid formation should be aggressively managed, if present.

First steps

  • Patient education is a cornerstone of management and must be detailed, honest, and repeated on subsequent visits. Management of the condition, rather than cure, may be the most realistic therapeutic strategy.
  • For persons with moderate to severe PFB, no shaving is recommended. They may be best served by always having a beard.
  • Daily lifting out of any ingrowing hairs with a needle, beard pick, or pointed toothpick is required. Brisk washing of the affected area with an exfoliating sponge or face cloth may also dislodge early ingrowing hairs. Do not pluck out hairs; simply lift out the ingrowing end.
  • Topical agents like benzoyl peroxide (to dry up pustules), topical retinoic acid, or mild keratolytic lotion (such as salicylic acid or glycolic acid) may be of some additional benefit and may be added to the shaving regimen.
  • Hydrocortisone 1 % cream or lotion should be applied after shaving and up to b.i.d., no matter what shaving technique is used. It reduces beard irritation.
  • Persons with active pustulation or moderate-to-severe involvement, if they want to attempt shaving in the future, must first grow a beard for 2-12 weeks to allow the bumps already present to resolve. During this period aggressive dislodgement of ingrowing hairs is performed.
  • Superficial chemical peels (such as glycolic acid or salicylic acid) may be a helpful adjunctive treatment for individuals with PFB and may also reduce secondary hyperpigmentation associated with this condition.
  • Laser epilation should always be considered as an important therapeutic option, when possible.

Shaving tips for patients with PFB

  • There are three basic forms of shaving available to the patient with PFB: razors, depilatories, and clippers. Each method will be discussed in detail below. Razor shaving is likely the most effective. Patients with PFB must take time when shaving and follow instructions carefully.
  • Razor shaving: One of three types of blade razors may be used: single-blade disposable, an adjustable razor set at the lowest setting (least close shave), or a foil-guarded system (PFB shaving system). All are effective, but the latter is probably the best. Razor shaving is usually effective in those with mild to moderate PFB. Electric razors are usually no better than blade razors.
    • Detailed instructions on the correct techniques are essential:
      • Dislodge all ingrown hairs.
      • Soak the beard with a shave cream for several minutes.
      • Shave with the grain using even, smooth strokes. Do not press down with the razor.
      • Do not stretch the skin when shaving.
      • Shave often enough to keep the beard hair an optimal length: long enough to be out of the follicle, but short enough to not be ingrowing. This varies from daily to every third day, depending on the rate of the beard growth of the patient.
  • Depilatory shaving: Two forms of depilatories are available: barium sulfide and calcium thiogylcolate. Depilatory shaving takes time, has an unpleasant smell, and is irritating. Due to their inherent irritancy, depilatories can rarely be used more often than twice weekly. Repeated applications enhance irritancy. It is generally more effective than razor shaving in those with moderate to severe disease.
    • Detailed instructions on the correct techniques are essential:
      • Mix the powder with cool water and apply a thin coat to one-fourth to one-half of the beard area. Applying to the whole beard at one time may allow paste to remain on the skin too long before removal.
      • Remove as soon as the beard hairs are dissolved, usually 2-3 minutes.
      • Scrape off the paste with a moist spatula or tongue blade using short rapid strokes in the direction of beard growth.
      • Wash the area thoroughly with cool water and soap to remove all residual paste. Residual depilatory will cause irritation.
      • Repeat steps on the remaining beard areas.
      • Apply hydrocortisone 1% cream after shaving and b.i.d.
  • Clipper shaving: Most patients with PFB will be able to trim their beard with triple “0” (zero) barber clippers with good results. The result is approximately a 1/16-inch stubble (“5 o’clock shadow”). Certain patients with mild-to-moderate PFB may be able to shave closer, after clipping, with a rotary triple-headed razor. A pre-shave is recommended when using clippers or rotary shavers.

Pitfalls

  • PFB may be misdiagnosed as acne vulgaris, pyoderma, or razor “allergy.” If there is any doubt refer the patient for evaluation.
  • Do not be disappointed by therapeutic failure. Work with the patient (and employer if necessary if having facial hair is a concern) and individualize the therapeutic plan, including hair removal.
  • Postinflammatory hyperpigmentation may occur from the PFB or from irritating topicals (i.e., depilatories, benzoyl peroxide, or retinoic acid).

When to refer to a dermatologist

  • If the diagnosis (or infectious cause) of folliculitis is not clear.
  • For management of chemotherapy-induced folliculitis.
  • For isotretinoin treatment of Gram-negative folliculitis.
  • For laser epilation for PFB.
  • For ongoing management of PFB, especially if there is extensive pigmentary alteration or keloid formation.

Clinical Cases

Case 1

  • 18-year-old healthy male college student
  • No significant past medical history
  • Review of systems is noncontributory
  • Presents for management of 7 days’ history of a pustular eruption on the face

Initial evaluation

  • Healthy appearing male
  • Scattered papules and pustules on the chin, upper cutaneous lip, and cheeks
  • Analysis of the pustular contents in the clinic does not reveal any organisms
  • Bacterial and viral cultures are taken
  • Recommend doxycycline 100 mg b.i.d. x 10 days
  • Follow-up in 2 weeks

Interim update

  • Bacterial culture does not reveal any organisms
  • Viral culture is notable for HSV-1
  • Diagnosis: herpetic folliculitis
  • The patient is notified; patient reports that he has not improved on the doxycycline regimen; doxycycline is discontinued and valcyclovir is started (lesions resolve)

Case 2

  • 19-year-old healthy male
  • No significant past medical history
  • Presents for evaluation and management of long-standing facial eruption that he believes is irritation due to shaving

Initial evaluation

  • Healthy appearing male
  • Extensive follicular-based papules and pustules in a beard distribution, numerous ingrown hairs and macules of postinflammatory hyperpigmentation noted
  • Diagnosis: pseudofolliculitis barbae
  • Extensive counseling regarding the goals of the therapeutic strategy
  • Recommend new strategies for shaving (as outlined above)
  • Recommend hydrocortisone 1% lotion applied every other day, with topical tretinoin 0.025% cream on alternating days
  • Follow-up in 6 weeks

Ongoing follow-up evaluation

  • Follow-up at 2- to 3-month intervals for 6 months
  • Condition is improving overall, though still persistent, and the postinflammatory pigmentary changes are also resolving
  • The patient starts a regimen of laser hair removal to the affected areas, which resolves his symptoms

References

Bridgeman-Shah S (2004). The medical and surgical therapy of pseudofolliculitis barbae, Derm Therapy, 17:158-163.

Elston DM (2007). Community-acquired methicillin-resistant Staphylococcus aureus, JAAD, 56(1):1-16.

Luelmo-Aguilar J, Santandreu MS (2004). Folliculitis: recognition and management, Am J Clin Dermatol, 5(5):301-10.