Skin Disorders Guide

Diagnostic Hallmarks

1. Distribution: the groin and exposed areas of the arms and legs
2. Bacterial culture
3. Response to therapy
   

   Clinical Presentation

   The small I-2-mm pustules of bacterial folliculitis are yellow-white in color and are surrounded by a narrow ring of erythema. Those that are pierced by a hair are acuminate (pointed), those that are not are dome-shaped. Only a few pustules are present at anyone time, and there is relatively little tendency for clustering. Fever and lymphadenopathy are not seen. The diagnosis of bacterial folliculitis is usually made on a clinical basis, but confirmation can tie obtained by Gram stain and bacterial culture.

Course and Prognosis

Individual untreated pustules resolve spontaneously in about a week, but often as quickly as one heals, one or more new pustules appear elsewhere on the body. This spread develops as the result of external inoculation via the fingernails. Hematogenous spread does not occur. On rare occasions bacterial folliculitis leads to deeper infection such as cellulitis or furunculosis.

Pathogenesis

Bacterial folliculitis usually represents infection of the upper hair follicle with Staphylococcus aureus. Streptococci also are occasionally found, but they rarely if ever are the inciting organism. A few cases of Pseudomonas sp. folliculitis have been reported. This uncommon and, often, rather severe type of folliculitis occurs as a result of contaminated water in hot tubs. Minor skin trauma of various sorts probably plays a role in the development of all types of bacterial folliculitis.

Therapy

Topical antibiotics may be used if only one or two pustules are present. Systemic antibiotics are preferred for patients who have a large number of lesions or who have problems with recurrent lesions. Some of these latter patients will be found to be staphylococcal carriers.