Folliculitis

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Images of Folliculitis

Overview

Folliculitis literally means "inflammation of the follicle," the follicle referring to the small pores that the hair shaft grows out of. The inflammation may appear on the outer surface of the skin or in deeper parts of the skin. If folliculitis occurs near the skin surface, it looks like a tiny, white pimple at the base of a hair and is filled with pus, which contains microorganisms, usually bacteria. These small pimples can range from one to many. A person with folliculitis may find that the inflammation is tender to the touch.

Who's at risk?

Folliculitis can occur in anyone, though certain conditions make the infection more likely to occur in a person, such as:

  • Irritation from shaving, sweat, clothing, or certain chemicals.
  • Trauma to the skin surface.
  • Living in warm, humid climates, which increases sweating.
  • People with cancer or diseases that suppress the immune system or who are receiving immune-suppressing therapy.
  • Having diabetes and/or being obese.
  • People with acne or other skin conditions, especially teens.
  • Chronic skin steroid therapy.

Signs and Symptoms

The most common locations for folliculitis include:

  • Scalp
  • Beard area in males who shave
  • Underarms, groin, or legs in females who shave
  • Buttocks
  • Thighs
Individual lesions of folliculitis include pus-filled bumps (pustules) centered on hair follicles. These pustules may be pierced by an ingrown hair, can vary in size from 2–5 mm, and are often surrounded by a rim of pink to red, inflamed skin. Occasionally, a folliculitis lesion can rupture to form a scab on the surface of the skin.

Mild and moderate cases of folliculitis are often tender or itchy. More severe cases of folliculitis, which may be deeper and may affect the entire hair follicle, may be painful.

Mild and moderate cases of folliculitis usually clear quickly with treatment and leave no scars. However, more severe cases of folliculitis may lead to complications such as cellulitis (an infection of the deeper skin tissue), scarring, or permanent hair loss.

Self-Care Guidelines

In order to prevent folliculitis, try the following:

  • Shave in the same direction of hair growth.
  • Avoid shaving irritated skin.
  • Use an electric razor or a new disposable razor each time you shave.
  • Consider other methods of hair removal, such as depilatories.
  • Avoid tight, constrictive clothing, especially during exercise.
  • Wash athletic wear after each use.
The following measures may help to clear up folliculitis if it is mild:
  • Use an antibacterial soap.
  • Apply hot, moist compresses to the involved area.
  • Try an over-the-counter corticosteroid lotion (cortisone) to help soothe irritated or itchy skin.
  • Launder towels, washcloths, and bed linens frequently, and do not share such items with others.
  • Wear loose-fitting clothing.

When to Seek Medical Care

Make an appointment to be evaluated by a dermatologist or by another physician if the above self-care measures do not resolve the folliculitis within 2–3 days, if symptoms recur frequently, or if the infection spreads.

Be sure to tell your doctor about any recent exposure to hot tubs, spas, or swimming pools, as a less common form of folliculitis may be caused by contamination from these water sources.

If you are currently being treated for a skin infection that has not improved after 2–3 days of antibiotics, return to your doctor.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a strain of "staph" bacteria resistant to antibiotics in the penicillin family, which have been the cornerstone of antibiotic therapy for staph and skin infections for decades. CA-MRSA previously infected only small segments of the population, such as health care workers and persons using injection drugs. However, CA-MRSA is now a common cause of skin infections in the general population. While CA-MRSA bacteria are resistant to penicillin and penicillin-related antibiotics, most staph infections with CA-MRSA can be easily treated by health care practitioners using local skin care and commonly available non-penicillin-family antibiotics. Rarely, CA-MRSA can cause serious skin and soft tissue (deeper) infections. Staph infections typically start as small red bumps or pus-filled bumps, which can rapidly turn into deep, painful sores. If you see a red bump or pus-filled bump on the skin that is worsening or showing any signs of infection (ie, the area becomes increasingly painful, red, or swollen), see your doctor right away. Many people believe incorrectly that these bumps are the result of a spider bite when they arrive at the doctor's office. Your doctor may need to test (culture) infected skin for MRSA before starting antibiotics. If you have a skin problem that resembles a CA-MRSA infection or a culture that is positive for MRSA, your doctor may need to provide local skin care and prescribe oral antibiotics. To prevent spread of infection to others, infected wounds, hands, and other exposed body areas should be kept clean and wounds should be covered during therapy.

Treatments Your Physician May Prescribe

Folliculitis is fairly easy to diagnose in most cases. Your physician may wish to perform a bacterial culture in order to determine the cause of the folliculitis. The procedure involves:

  1. Penetrating the pustule with a needle, scalpel, or lancet
  2. Rubbing a sterile cotton-tipped applicator across the skin to collect the pus
  3. Sending the specimen away to a laboratory
Typically, the laboratory will have preliminary results within 48–72 hours if there are many bacteria present. However, the culture may take a full week or more to produce final results. In addition to identifying the strain of bacteria that is causing the folliculitis, the laboratory usually performs antibiotic sensitivity testing in order to determine the medications that will be most effective in killing off the bacteria.

Depending on bacterial culture results, your physician may recommend the following treatments:
  • Prescription-strength antibacterial wash such as hexachlorophene
  • Topical antibiotic lotion or gel such as erythromycin or clindamycin
  • Oral antibiotic pills such as cephalexin, erythromycin, or azithromycin
Occasionally, the bacteria causing the infection are resistant to treatment with commonly used antibiotics (methicillin-resistant Staphylococcus aureus, or MRSA). MRSA bacteria can sometimes cause a more severe form of folliculitis. Depending on the circumstances, your doctor may consider more aggressive treatment that includes prescribing:
  • A combination of two different oral antibiotics, including trimethoprim-sulfamethoxazole, clindamycin, amoxicillin, linezolid, or a tetracycline.
  • A topical medication, mupirocin ointment, to apply to the nostrils.
If your doctor prescribes antibiotics, be sure to take the full course of treatment.

Trusted Links

Clinical Information and Differential Diagnosis of Folliculitis

References

L., ed. Dermatology, pp.211, 241, 553-566. New York: Mosby, 2003.

Freedberg, Irwin M., ed. Fitzpatrick's Dermatology in General Medicine. 6th ed, pp.1845, 1250, 1860, 1901. New York: McGraw-Hill, 2003.