Folliculitis is an infection of hair follicles. Diagnosis is clinical. Treatment for most cases of bacterial folliculitis is with topical mupirocin or clindamycin.
(See also Overview of Bacterial Skin Infections.)
The etiology of folliculitis is often unclear, but perspiration, trauma, friction, and occlusion of the skin are known to potentiate infection.The pathogen may be bacterial, fungal, viral, or parasitic.
Bacterial folliculitis is usually caused by Staphylococcus aureus, but occasionally Pseudomonas aeruginosa (hot tub folliculitis) or other organisms have been reported. Hot tub folliculitis occurs because of inadequate chemical treatment of water.
Acne is a noninfectious form of folliculitis.
Symptoms and Signs of Folliculitis
Symptoms of folliculitis are mild pain, pruritus, or irritation.
Signs of folliculitis are a superficial pustule or inflammatory nodule surrounding a hair follicle. Infected hairs easily fall out or are removed by the patient, but new papules tend to develop.
Growth of stiff hairs into the skin may cause chronic low-grade irritation or inflammation that may mimic infectious folliculitis (pseudofolliculitis barbae).
Folliculitis
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Folliculitis manifests as superficial pustules or inflammatory nodules surrounding hair follicles.
Image provided by Thomas Habif, MD.
Diagnosis of Folliculitis
Clinical evaluation
The primary skin finding in folliculitis is a pustule and perifollicular inflammation.
Microbiologic testing is not routinely indicated.
Treatment of Folliculitis
Topical antibiotics
Sometimes systemic antibiotics
Because most folliculitis is caused by S. aureusS. aureus (MRSA) etiology, and nares are cultured to rule out nasal staphylococcal carriage.
Potassium hydroxide wet mount should be done on a plucked hair to rule out fungal folliculitis.
Hot tub folliculitis usually resolves without treatment. However, adequate chlorination of the hot tub is necessary to prevent recurrences and to protect others from infection.
Key Points
Folliculitis can be caused by various pathogens and tends to be potentiated by perspiration, trauma, friction, and occlusion of the skin.
Bacterial folliculitis is usually caused by Staphylococcus aureus but occasionally Pseudomonas aeruginosa (hot tub folliculitis).
