Folliculitis

Folliculitis is a common infection of the hair follicle most often caused by Staphylococcus.
Bacterial folliculitis is also discussed in Chapter 16: Superficial Bacterial Infections, Folliculitis, and Hidradenitis Suppurativa.

Lesions present as perifollicular pink papules and pustules (Fig. 5.4).
In children, folliculitis most commonly occurs on the scalp, thighs, back, and buttocks.
In adolescents, the back and chest are frequently involved (Fig. 5.5).
In adolescent girls, the legs and axillae are common sites.

Irritant folliculitis commonly occurs on the buttocks or areas of occlusion and friction in children.
Risk factors for irritant folliculitis are occlusion/maceration, heat/humidity, shaving/plucking/waxing, topical steroids, diabetes, and atopic dermatitis.
Commonly seen on the buttocks in school-aged children.
Can be seen on the legs of adolescent girls.

Differential Diagnosis

Keratosis Pilaris

Grouped keratotic perifollicular papules with rough texture.
Typically located on the arms, lateral cheeks, or extensor thighs in children.

Acne

Miliaria Rubra

Erythematous papulovesicles seen in occluded areas of the body such as the body folds and the back in infants.

Pityrosporum Folliculitis

Erythematous perifollicular papules on the back and chest of young adults caused by Malassezia furfur.
Resembles acne or folliculitis but is resistant to the typical acne treatments.

Management

Uncomplicated superficial folliculitis can be treated with antibacterial soaps, good hygiene, and topical antibiotics.
Mupirocin ointment applied twice daily to affected areas is useful for localized cases.
Clindamycin 1% solution, gel or lotion twice daily, is commonly used for folliculitis of the chest and back.
Antibacterial soaps should be used in conjunction with topical antibiotics.
Benzoyl peroxide 3% to 10% wash (PanOxyl, Oxy10) or chlorhexidine wash (Hibiclens) are often recommended.
A novel sodium hypochlorite body wash (CLn wash, available at www.clnwash.com) is an effective antibacterial alternative that may be less irritating.
Refractory, widespread, or deeper infections may require systemic antibiotics.
First-line treatment is with a beta-lactamase-resistant penicillin, or a cephalosporin such as cephalexin.
Untreated folliculitis can result in a deeper infection including furuncles, carbuncles, or cellulitis.

Point to Remember

Moisture and occlusion under tight fitting athletic clothes or equipment can be a precipitating factor for folliculitis.