Folliculitis

Causes include bacterial, fungal, viral, and parasitic microorganisms.

Most commonly superficial and resulting from infection by Staphylococcus aureus; use of antibacterial soaps may suffice as treatment for uncomplicated folliculitis, which is self-limited.

Deeper infection and inflammation of hair follicles from Staphylococcus aureus generally require systemic antibiotic therapy based on culture sensitivities.

Other common infectious agents include gram-negative organisms, fungi, viruses, and parasites; can occur in acne patients undergoing long-term oral antibiotic therapy and may mimic an acne flare.

Treatment is tailored to the underlying cause; hygienic measures, MRSA eradication, and symptomatic therapies are other important treatment modalities to consider.

Folliculitis is an inflammatory process involving any part of the hair follicle; it is most commonly secondary to infection. It is important to recognize noninfectious causes of folliculitis (e.g., eosinophilic folliculitis) as well as folliculitis primarily involving the scalp (e.g., folliculitis decalvans). The condition manifests clinically as erythematous papules or pustules around hair follicles. Depending on the etiology and chronicity of the condition, histologic examination reveals various populations of inflammatory cells around the pilosebaceous unit. Folliculitis commonly occurs in areas with terminal hair growth, such as the head and neck region, axillae, groin, and buttocks; it also favors areas under occlusion.