Folliculitis is infection and inflammation of the hair follicles. The condition may be superficial (i.e., on the surface of the skin) or deep within the follicles. Hair follicles become red and irritated, and pus-filled lesions form. Folliculitis can clear up by itself in a matter of a couple of weeks or become more persistent and thus require treatment.

Causes and Risk Factors

The most common cause of folliculitis is infection by the bacteria Staphylococcus aureus. Other species of bacteria may also be responsible. For example, contaminated water in whirlpools and hot tubs can transmit Pseudomonas aeruginosa, which can cause folliculitis. This bacterium may also be passed in wet suits.

Fungal and viral infections can also cause the condition. These are not common, but doctors may suspect these agents if conventional treatments do not work. Viral infections may be more common in those with compromised immune systems, such as AIDS, organ transplant, and cancer patients.

Folliculitis symptoms can appear independent of infection. Exposure of the skin to certain chemicals, especially oils and tars, can trigger an outbreak. People with depressed immune systems, diabetes, or obesity have a greater risk of contracting folliculitis than the general population.

Signs and Symptoms

An early sign of folliculitis is a small white or yellow pus-filled lesion (pustule) on a red, inflamed follicle. The most likely starting points are the scalp, thighs, legs, and buttocks.

When an infection of the follicle goes deeper, it becomes a boil or furuncle. A group of closely packed boils create a larger lesion called a carbuncle. These lesions tend to occur in hairy, sweaty areas of the body.

Other Resources:

"Hot Tub Rash" Pseudomonas Dermatitis / Folliculitis

Source: Centers for Disease Control
Last Updated 4-12-2008