SymptomsBy Mayo Clinic staff
Folliculitis signs and symptoms vary, depending on the type of infection.
Superficial folliculitis, which affects the upper part of the hair follicle, may cause:
- Clusters of small red or pus-filled bumps that develop around hair follicles
- Pus-filled blisters that break open and crust over
- Red and inflamed skin
- Itchiness or tenderness
Deep folliculitis starts deeper in the skin surrounding the hair follicle and affects the entire hair follicle. Signs and symptoms include:
- A large swollen bump or mass
- Pus-filled blisters that break open and crust over
- Possible scars once the infection clears
Types of superficial folliculitis
Superficial forms of folliculitis include:
- Staphylococcal folliculitis. This common type is marked by itchy, white, pus-filled bumps that can occur anywhere on your body where hair follicles are present. When it affects a man's beard area, it's called barber's itch. It occurs when hair follicles become infected with Staphylococcus aureus (staph) bacteria. Although staph bacteria live on your skin all the time, they generally cause problems only when they enter your body through a cut or other wound. This can occur through shaving, scratching or with an injury to the skin.
- Pseudomonas folliculitis (hot tub folliculitis). The pseudomonas bacteria that cause this form of folliculitis thrive in a wide range of environments, including hot tubs in which the chlorine and pH levels aren't well regulated. Within eight hours to five days of exposure to the bacteria, a rash of red, round, itchy bumps will appear that later may develop into small pus-filled blisters (pustules). The rash is likely to be worse in areas where your swimsuit holds contaminated water against your skin.
- Pseudofolliculitis barbae. An inflammation of the hair follicles in the beard area, pseudofolliculitis barbae affects men when shaved hairs curve back into the skin. This leads to inflammation and, sometimes, to dark raised scars (keloid scars) on the face and neck.
- Pityrosporum folliculitis. Especially common in teens and adult men, pityrosporum folliculitis is caused by a yeast and produces chronic, red, itchy pustules on the back and chest and sometimes on the neck, shoulders, upper arms and face.
Types of deep folliculitis
Types of deep folliculitis include:
- Sycosis barbae. This occurs in men who have begun shaving and involves inflammation along the whole hair follicle. Small pustules appear at first on the upper lip, chin and jaw, then become more prevalent as shaving continues. Severe sycosis barbae may cause scarring. Gram-negative folliculitis. This sometimes develops if you're receiving long-term antibiotic treatment for acne. Antibiotics alter the normal balance of bacteria in the nose, leading to an overgrowth of harmful organisms (gram-negative bacteria). In most people, this doesn't cause problems, and the flora in the nose returns to normal once antibiotics are stopped. In a few people, however, gram-negative bacteria spread and cause new, sometimes-severe acne lesions.
- Boils and carbuncles. These occur when hair follicles become deeply infected with staph bacteria. A boil usually appears suddenly as a painful pink or red bump. The surrounding skin also may be red and swollen. The bump then fills with pus and grows larger and more painful before it finally ruptures and drains. Small boils usually heal without scarring, but a large boil may leave a scar. A carbuncle is a cluster of boils that often occurs on the back of the neck, shoulders, back or thighs. Carbuncles cause a deeper and more severe infection than does a single boil. As a result, they develop and heal more slowly and are likely to leave scars.
- Eosinophilic folliculitis. Seen primarily in those with HIV, this type of folliculitis is characterized by recurring patches of inflamed, pus-filled sores, primarily on the face and sometimes on the back or upper arms. The sores usually spread, may itch intensely and often leave areas of darker than normal skin (hyperpigmentation) when they heal. The exact cause of eosinophilic folliculitis isn't known, although it may involve the same yeast-like fungus responsible for pityrosporum folliculitis.
When to see a doctor
Mild cases of folliculitis often clear up without any treatment. But if the infection doesn't improve despite home care, appears to spread or recurs often, call your doctor or a dermatologist. You may need antibiotics or antifungal medications to help control the problem.
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