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Staphylococcal Folliculitis !!navigator!!

Clinical Manifestations

  • Bacterial folliculitis is most often caused by infection with coagulase-positive S. aureus.

  • Lesions typically elicit mild discomfort or tenderness and occasionally itch.

  • The primary lesion is an erythematous pustule or papule with a central hair (Figs. 16.9-16.10). The central hair shaft may not always be visible.

  • Follicular lesions tend to manifest a grid-like pattern on hair-bearing areas of the body.

  • Lesions are often polymorphic, displaying a mixture of papules and pustules, or they may be monomorphic and consist solely of papules.

  • In darkly pigmented patients, hyperpigmented macules or papules arranged in a follicular pattern may be all that is clinically apparent.

Distribution of Lesions

  • Lesions occur on hair-bearing areas—the face, scalp, thighs, and body folds.

  • The axillae, groin, and legs are particularly prone to folliculitis when they are regularly shaved.

Clinical Variants

  • Tender, painful, folliculitis involving an eyelash is called a hordeolum or “stye.”

  • Similarly, folliculitis may affect a single nasal hair follicle and may produce a tender erythematous papule or pustule in or on the distal nose or near the tip of the nose (Fig. 16.11).

Diagnosis

  • Bacterial folliculitis is generally diagnosed by clinical findings. In cases that are resistant to treatment, the following procedures may be performed:

    • Gram stain: typically demonstrates gram-positive cocci.

    • Bacterial culture: grows S. aureus.

Diagnosis-icon.jpg Differential Diagnosis

Acne Vulgaris/Acne-like Conditions

  • Acneform papules and pustules may be indistinguishable from folliculitis.

Keratosis Pilaris

  • Because this condition involves the hair follicles, it manifests in a grid-like pattern, similar to that of folliculitis.

  • Central punctum is keratotic rather than pustular.

Insect Bite Reactions

Management-icon.jpg Management

Initial Episode

  • Mild cases of bacterial folliculitis can sometimes be prevented or controlled with antibacterial soaps such as benzoyl peroxide or Hibiclens.

  • In addition, topical antibiotics, such as erythromycin 2% topical solution or clindamycin (Cleocin) 1% solution, may be applied once or twice a day to the affected areas.

  • For more widespread or severe cases, systemic antibiotics such as dicloxacillin (250 to 500 mg four times a day) or a cephalosporin, such as cephalexin (1 to 4 g/day in two doses) are generally the first choices.

Chronic and Recurrent Cases

  • If staphylococcal colonization is present, mupirocin 2% (Bactroban) ointment should be applied to the nasal vestibule twice a day for 5 days monthly × 3 months to eliminate the S. aureus carrier state.

  • Family members may be treated similarly, if necessary. Rifampin (600 mg/day for 10 to 14 days) may also help eliminate the carrier state.

Point-Remember-icon.jpg Points to Remember

  • Bacterial cultures should be considered for cases that are resistant to therapy.

  • Culturing and treating of family members should be considered in cases of chronic bacterial folliculitis.

Pseudomonas Folliculitis (“Hot Tub Folliculitis”) !!navigator!!

Clinical Manifestations

  • Pruritic lesions occur 1 to 3 days after bathing in a hot tub, whirlpool, or public swimming pool.

  • Lesions of hot tub folliculitis consist of intensely pruritic or tender follicular papules or pustules that are most often found on the trunk, particularly on areas covered by a bathing suit (Fig. 16.12).

Diagnosis

  • The diagnosis is based on clinical appearance and a history of exposure.

  • Pseudomonas organisms may be isolated in patients with this condition.

Management-icon.jpg Management

  • Hot tub folliculitis usually resolves spontaneously, but it may persist if it is very extensive or symptomatic.

  • If necessary, oral ciprofloxacin (500 mg twice a day for 5 days) will lead to resolution.

Outline