Folliculitis is an infection of the hair follicles in the skin. It is a common problem that is not usually serious. Tiny pus-filled spots (pustules) develop at the base of a hair, often in crops. Mild cases often resolve without treatment. Sometimes, antibiotic creams or tablets are needed. In recurrent cases, antiseptic skin washes can be used.
What is folliculitis?
Folliculitis means an inflammation or infection of the hair follicles of the skin. Most of the skin is covered with tiny hairs which grow out of hair follicles. In folliculitis, many hair follicles in one area of the skin are affected.
The affected hair follicles swell into small pus-filled pimples. Each individual pimple looks like a small, rounded, yellow-red spot.
Why does folliculitis occur?
Most cases of folliculitis are due to an infection with a germ (bacterium) called Staphylococcus aureus (S. aureus). This bacterium is carried harmlessly in the noses of many people, without causing any problems. Occasionally, other germs (bacteria) are the cause of folliculitis.
Folliculitis usually occurs at sites where hair follicles are damaged by friction or shaving, or where there is blockage of the follicle. Excessive sweating (hyperhidrosis) due to overactivity of the sweat glands can be another cause. Sometimes, using a steroid cream on the face can trigger a bout of folliculitis. The most common site affected is the beard area of men. Other common sites for folliculitis are the arms, legs, armpits and buttocks.
Types of folliculitis
Folliculitis can occur anywhere on hair-bearing skin. (It could not, for example, occur on the palms of the hands where there is no hair.) There are a few specific types of folliculitis that deserve a mention:
- Sycosis barbae - this is the medical name for a long-term (chronic) folliculitis in the beard area of the face in men. It often affects the upper lip and it can be difficult to treat. The skin is painful and crusted, with burning and itching on shaving. Numerous pustules develop in the hair follicles. Some men grow a beard to solve the problem.
- Hot tub folliculitis - as the name suggests, this tends to affect people who use hot tubs a lot. The hot water encourages germs (bacteria) called Pseudomonas spp. to grow (particularly if there is not enough chlorine in the water to keep it clean). Bathing in this 'soup' of bacteria can increase your risk of folliculitis. 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.
- Gram-negative folliculitis - this is a type of folliculitis that may occur after acne has been treated with long-term antibiotics. Different bacteria are involved (not staphylococci). Gram-negative refers to a type of stain that is used in a laboratory to identify different types of bacteria.
- Pseudo-folliculitis - this is not really a true folliculitis. It does look similar, as little lumps form at the bases of hairs. These lumps do not contain pus. They are actually due to ingrowing hairs. Sometimes this problem causes scarring. Pseudo-folliculitis is more common in people with curly or Afro-Caribbean hair.
As mentioned above, these can cause a condition that looks like folliculitis. They are hairs that have curled around and grown back into the skin. Anyone can have ingrowing hairs (also called ingrown hairs), but they are more common in people who have very curly or coarse hair. Curly hair is more likely to bend back and re-enter the skin, especially after it's been shaved or cut. Ingrowing hairs may also be caused by dead skin cells blocking the hair growing as normal.
Ingrowing hairs often irritate the skin and make a raised, red bump (or group of bumps) that looks like a little pimple. Sometimes the bump(s) can be painful. In men, ingrowing hairs often pop up as a bunch of little bumps on the chin, cheeks, or neck after they've shaved. In women they often occur on the legs or bikini area.
Often an ingrowing hair will go away on its own. If it doesn't go away, an ingrowing hair can become infected, make the skin dark, or leave a scar. This is more likely if you've been scratching or picking the hair.
Folliculitis and other skin infections
Furuncles and carbuncles are the medical names for what you would call a boil. Both are skin infections caused by germs (bacteria) - usually S. aureus. A furuncle is a skin infection that involves the hair follicle and surrounding skin. Clusters of furuncles can join together under the surface of the skin, forming a carbuncle. A carbuncle means the infection has spread more deeply in the skin and scarring is more likely. Carbuncles and furuncles are generally much bigger and more painful than the tiny pustules you get in folliculitis. They may need to be cut into (incised) and drained (lanced) to let the pus out.
Sometimes acne can look similar to folliculitis too. The main difference is that in acne, the hair follicles become plugged with oils (from glands in the skin) and dead skin cells. There may also be an overgrowth of certain bacteria that can live in hair follicles.
What is the treatment for folliculitis?
General measures involve avoiding things that aggravate the condition. It is important to shave in the direction of hair growth. Sometimes it is worth taking a break from shaving for a few days, to let the folliculitis settle down by itself. Tight clothing over the affected area, particularly if it makes you sweat, will not help either. Keeping cool and keeping folliculitis exposed to the fresh air will also help. If you have folliculitis you should not share towels, flannels or razors.
Most cases or 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 or lotion or Emulsiderm®. This will improve the condition of the skin and soothe it. It 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. Specific preparations for the bath or shower are available - for example, Dermol® 200 Shower Emollient, Dermol 600® Bath Emollient and Oilatum® Plus bath additive.
If simple measures over a few days do not allow the folliculitis to improve, you should probably see your GP for further advice and treatment.
For localised areas of folliculitis, an antibiotic cream may be useful. Fusidic acid (Fucidin® cream) is a suitable antibiotic cream that can be applied 3-4 times per day to affected areas.
More severe cases
If the folliculitis is more severe or widespread then a course of 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, your GP may take a sample (swab) from the skin where the folliculitis is. This swab can show what germs (bacteria) are responsible for the infection. If the swab confirms S. aureus, it is a good idea to take some more swabs, usually from the nose, to see if you are a carrier of this bacterium.
If you do carry staphylococci in the nose and you get recurrent folliculitis (or if you have chronic folliculitis), this is likely to be the reason behind it. Treatment is to destroy (eradicate) the staphylococci and prevent further folliculitis. This will usually involve three forms of treatment to be used at the same time. Firstly, a course of antibiotic tablets. Secondly, a course of an antibiotic nasal cream. Because the staphylococci may also be on other parts of the body, not just where the folliculitis is, it is also advisable to use an antiseptic skin wash or shower gel. Products containing chlorhexidine (for example, Hibiscrub® 4% solution or Hydrex® 4% surgical scrub) or Ster-Zac Bath Concentrate®) are suitable. You should also launder clothing, bed linens and towels on a hot wash. Finally, you will need to have repeat swabs to confirm that you are clear of the bacteria - three clear swabs over a three-week period will confirm the staphylococcal infection has been eradicated.
Are there any complications of folliculitis?
Usually, folliculitis is a mild, non-serious problem that does not lead to complications. In fact, often it is self-limiting which means that it gets better on its own, without treatment.
Sometimes people develop problems with recurrent or long-term (chronic) folliculitis (see above), which could be seen as a complication.
Uncommonly, infection in the hair follicle can spread deeper or to surrounding tissues, leading to boils (furuncles or carbuncles - see above). A generalised skin infection called cellulitis can occur. This can usually be treated with a course of antibiotic tablets. Occasionally, cellulitis can be more serious and spread. This may need antibiotics given directly into a vein in hospital but this would be very rare to have happened because of folliculitis.
When people have had carbuncles or more extensive infections, scarring of the skin can be the result.
Can folliculitis be prevented?
Keeping your skin clean, dry and free from abrasions or irritations can help to prevent folliculitis. Certain people are more prone to infections, such as people with diabetes. If you have a medical problem that makes you more likely to get infections, these precautions may be more important. Using antiseptic washes routinely is not generally recommended, as they can make the skin sore and dry. Keeping the skin moisturised can help protect it from damage. Take care when shaving (especially if you wet shave), using a shaving gel, foam or soap to lubricate the blades across the skin and prevent nicks and cuts.
Dr Tim Kenny
Dr Laurence Knott
Dr Helen Huins