Folliculitis

What is folliculitis?

Folliculitis means inflammation of the hair follicles. Folliculitis can be a mild, short-lived condition or a severe long-term problem. Folliculitis can occur anywhere on hair-bearing skin. There are a number of causes of inflammation which can result in folliculitis.

Rash of folliculitis

James Heilman, MD, CC BY-SA 3.0, via Wikimedia Commons

Folliculitis symptoms

• When hair follicles become infected or inflamed they swell causing a red bump on the skin.

• Sometimes the affected follicles fill with pus, covering the affected skin with small, rounded, yellow-red spots (pustules).

• Affected skin may develop a crust, which can be yellow or golden coloured due to infection.

• The affected skin can feel painful, hot and may be itchy.

Folliculitis locations

Folliculitis can be found everywhere where hair grows but the following areas are particularly common:

• Buttocks.

• Legs.

• Back.

• Chest.

• Face.

• Scalp.

Types of folliculitis

Bacterial folliculitis

This is the commonest type of folliculitis and usually arises from the typical bacteria which normally live on the skin causing an infection in the hair follicles. It is very common and easily treated with antibiotics if it is significant enough to need treatment. Often it will settle on its own without treatment.

There are a few specific types of folliculitis:

Sycosis barbae

This is the medical name for a long-term (chronic) folliculitis in the beard area of the face. The skin is painful and crusted, with burning and itching on shaving. Numerous pustules develop in the hair follicles. It can be difficult to treat and some men grow a beard to solve the problem.

Hot tub folliculitis

As the name suggests, this tends to affect people after using a hot tub. The hot water encourages a bacteria called Pseudomonas aeruginosa to grow (particularly if there is not enough chlorine in the water to keep it clean). This type of folliculitis is generally harmless and is prevented by proper maintenance of hot tubs. Showering after using the hot tub does not seem to reduce the chance of folliculitis. Antibiotics are not needed for hot tub folliculitis; it usually settles within 2 weeks.

Gram-negative folliculitis

This is a type of folliculitis that may occur after acne has been treated with long-term antibiotics. Gram-negative refers to a type of stain that is used in a laboratory to identify different types of bacteria.

Pseudo-folliculitis

Also known as "razor bumps", this is caused by inflammation from shaving and ingrowing hairs. Pseudo-folliculitis is more common in people with curly or Afro-Caribbean hair, as these hairs are more likely to curl back and grow into the skin. Ingrowing hairs can also be caused by dead skin cells blocking the hair follicle so the hair cannot exit the follicle.

Malassezia folliculitis

Also known as pityrosporum folliculitis, this is caused by yeasts which normally live on the skin but occasionally cause inflammation. Malassezia folliculitis is more common in adolescent boys and young men and is also more common in hot humid climates. Other things that make malassezia folliculitis more common are frequent use of sunscreen, excessive sweating, antibiotic use and the immune system being impaired.

Folliculitis

Ran Yuping et al., CC BY-SA 3.0, via Wikimedia Commons

Eosinophilic folliculitis

This rare form of folliculitis is also known as eosinophilic pustular folliculitis or Ofuji disease. It causes itchy pustules and is more common in men than women. The pustules are usually seen on the head, neck and trunk and can persist for weeks or months. It may look like acne. It is associated with HIV but also occurs in people without HIV. Simple anti-inflammatory drugs have been reported to help in up to 7 out of 10 people with eosinophilic folliculitis. Antibiotics may also help.

Carbuncles

A carbuncle is a group of inflamed follicles close together which then join together into one hot red lump with pus coming out of several points. This can be very painful and antibiotics are often needed. Warm compresses may help avoid the need for antibiotics.

Furuncles (boils)

This is an infection deeper in the hair follicle which causes a small abscess just under the skin. It is hot and red. Antibiotics may be needed but warm compresses can often help.

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Causes of folliculitis

Folliculitis occurs at sites where hair follicles are inflamed. There are a number of causes:

• Infection. Most folliculitis infections are caused by a bacteria called Staphylococcus aureus (S. aureus), which usually lives harmlessly on the skin. Occasionally other bacteria, fungi (Pityrosporum or Candida albicans) or parasites are the cause.

• Physical irritation caused by shaving or friction.

• Chemical irritation caused by chemicals applied to the skin.

• Blockage of the hair follicle eg, by dead skin cells or thick creams.

• Excessive sweating (hyperhidrosis) due to overactivity of the sweat glands.

• Steroid creams.

• Inflammatory skin conditions are an uncommon cause.

Complications of folliculitis

Most cases of folliculitis get better without any complications. Occasionally the following can occur:

• Scarring of the skin.

• Darkening of the affected skin (hyperpigmentation).

• Hair loss at the affected site due to scarring of the skin.

• Deep folliculitis. This occurs if the infection spreads deeper into the follicles causing a boil.

• Cellulitis. This is when infection spreads into the surrounding skin, making it hot and red.

Medical advice should be sought if there is an infection which is spreading deeper or onto surrounding skin.

Diagnosing folliculitis

There are no specific tests for folliculitis. Normally the diagnosis is obvious from the type of rash.

Occasionally a swab might help if there is discharge from the pustules.

Folliculitis treatment

Identifying the cause of the folliculitis will help decide what will help. General measures include:

• Avoiding things that aggravate the condition.

• Taking a break from hair removal until the folliculitis has settled down.

• Avoiding wearing tight clothes over the affected area, particularly if it causing sweating.

• Keeping cool and keeping folliculitis exposed to the fresh air.

• Not sharing towels, flannels or razors.

• Applying an antibacterial moisturiser (emollient) and soap substitute. See below for more information.

Mild cases

Most cases of folliculitis are mild and do not need any treatment. It often clears without any treatment within 7-10 days.

It may be helpful to use:

• A moisturiser (emollient) which contains an antibacterial agent - for example, Dermol® cream.

• Lotion or Emulsiderm®.

These may help the folliculitis to clear more quickly and reduce the risk of it becoming worse. You can use one of these emollients as a soap substitute until the folliculitis has cleared (and long-term if needed). These can also be added to the bath or shower - specific bath or shower products are not needed.

If simple measures over a few days do not result in improvement of the folliculitis, medical advice should be sought for further advice and treatment.

Localised folliculitis

For localised areas of folliculitis, an antibiotic cream may be useful. Fusidic acid is a suitable antibiotic cream that can be applied 3-4 times per day to affected areas. If the folliculitis is thought to be fungal, a different treatment may be used.

More severe cases

If the folliculitis is more severe or widespread then a course of oral antibiotic tablets may be needed.

Recurrent or long-term (chronic) folliculitis

Recurrent folliculitis occurs when the infection keeps coming back, although it disappears with treatment. The gaps between episodes may get shorter and, eventually, chronic folliculitis is the result.

In these cases, a clinician may take a sample (swab) from the skin where the folliculitis is. This swab can show if an infection is responsible and identify which type of infection it is. The correct medication can then be used to try and eradicate the bacteria from the skin.

Preventing folliculitis

To try and prevent folliculitis, the following actions may help:

• Keeping skin clean, dry and free from abrasions or irritations.

• Keeping skin well-moisturised.

• Using clean, sharp razors and shaving in the direction of hair growth, or using an electric razor.

• Using a shaving soap, gel or foam to lubricate the blades across the skin to help prevent nicks and cuts.

• Using hair removal methods other than shaving.

• Avoiding chemicals or items which irritate the skin.

• Exfoliating regularly to remove dead skin cells.

Using antiseptic washes routinely is not generally recommended as they can make the skin sore and dry.

Is folliculitis contagious?

Folliculitis itself is not contagious. In hot-tub folliculitis, other people who have been exposed to the same hot tub are likely to develop folliculitis as well.