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What is folliculitis?
Folliculitis is an inflammation of follicles, the skin structures that surround every individual hair on your body. This inflammation results in red bumps on your skin that may also be itchy, filled with pus, or covered by a hard crust.
In rare cases, the infection responsible for folliculitis may spread deeper within the skin, or into surrounding hair follicles. When this occurs, boils, scarring or permanent hair loss can occur. However, folliculitis usually clears up on its own, or following treatments with simple antiseptics or antibiotics.
Folliculitis is generally caused by a bacterial infection of your hair follicles. In most cases it is due to the bacteria Staphylococcus aureus.
The infection may be related to skin irritation from:
- Heavy sweating;
- Tight clothing;
- Adhesive dressings;
- Ingrown hairs from plucking, shaving, waxing or electrolysis;
- Injuries that cause a break in the skin, or;
- Conditions that result in inflammation, such as acne or eczema.
Less commonly, folliculitis can result from infection with a fungus, virus or mite.
Risk factors for folliculitis include:
- Wearing tight or restrictive clothing for long periods;
- Having thick, curly hair;
- Long-term use of certain medications, such as antibiotics or corticosteroids;
- Exposure to spa pools or heated swimming pools, and;
- A weakened immune system, due to an underlying medical condition such as diabetes, leukaemia or HIV/AIDS.
Folliculitis may be broadly classified as either superficial or deep, depending on what part of the hair follicle is infected.
Superficial folliculitis affects only the upper part of the hair follicle, at the surface of the skin. Types of superficial folliculitis include:
Staphylococcal folliculitis takes its name from the bacteria that cause the infection - Staphylococcus aureus, or 'staph' for short. These bacteria normally live on the skin, only causing problems when they enter the body through a cut, scratch or wound. Staphylococcal folliculitis appears as white, itchy, pus-filled bumps.
This common type of folliculitis can occur anywhere on the body where hair grows. When it occurs in a beard, the infection is often known as 'barber's itch'.
Also known as 'spa pool folliculitis', this type of folliculitis tends to arise within hours or a few days of bathing in warm water with low chlorine levels. A particular type of bacteria, Pseudomonas aeruginosa, thrives in this environment. This type of folliculitis is characterised by a rash of round, red bumps under your swimsuit that may develop into pus-filled blisters.
Pityrosporum folliculitis is caused by fungal yeasts from the Malassezia family. These yeasts are usually harmless and are found on the skin of most adults. However, their numbers tend to increase under tight, sweaty clothes. Pityrosporum folliculitis is particularly common in teenagers and men. Infection appears as red, pus-filled bumps on the back, arms and chest.
Oil folliculitis is caused by workplace exposure to various oils such as paraffin, wool fats, crude oil and coal tar. As some skin medications for eczema and psoriasis contain coal tar, they can also cause oil folliculitis. This condition appears on the forearms and thighs as small, red blisters.
Also known as 'ingrown hairs', pseudofolliculitis results from shaving, waxing or plucking the hair follicle. It can occur on any area of the skin, including the face, legs, neck and scalp. Pseudofolliculitis results in inflamed bumps that may or may not contain pus.
Deep folliculitis occurs deeper in the skin and affects the entire hair follicle. Sometimes scarring can occur once the infection has cleared. Types of deep folliculitis include:
A deep infection of the hair follicles and the skin around them in the beard. This type of infection can cause activation of the immune system. The inflammation can spread into surrounding hair follicles.
Occasionally, prolonged use of antibiotic medications for acne can lead to the selective overgrowth of particular bacteria, called gram-negative bacteria, in protected areas such as the nasal cavity. From there bacteria can potentially spread to hair follicles on the face, and cause gram-negative folliculitis.
Eosinophilic folliculitis occurs when a particular type of white blood cell, known as an eosinophil, is found in the infected hair follicles. Also known as Ofuji disease, this type of folliculitis is rare and most commonly seen in people with HIV/AIDS.
Steroid medications are a well-known cause of folliculitis. These medications may be applied to the skin as a cream or ointment, taken as a tablet, or injected. Other names for steroid medications include corticosteroids, glucocorticoids or cortisones.
When one or more eyelash follicles are infected, the condition is known as a stye. This type of folliculitis can appear on the inside or outside of the eyelid as a painful, red lump. Most styes clear up within a few days, with no treatment. The medical term for a stye is a hordeolum or chalazion.
Signs and symptoms
Folliculitis can occur anywhere on the body where hair grows, but is most commonly found on the legs, armpits, buttocks, face, scalp or groin.
The following symptoms may be seen around one or more hair follicles:
- Small, red bumps (papules);
- Clusters of pus-filled bumps that look like pimples (pustules);
- Red, itchy or painful skin, and;
- Crusting if the bumps burst.
Methods for diagnosis
Your doctor will most likely diagnose folliculitis by looking at your skin and asking questions about your symptoms. If the condition does not respond to treatment or comes back over time, a skin swab may be taken for further testing in a laboratory.
In the rare event that your doctor suspects eosinophilic folliculitis, a small tissue sample (biopsy) may be taken for analysis.
Types of treatment
Mild folliculitis often clears without treatment in around 7-10 days. For more severe cases that are ongoing or keep coming back, the treatment options will depend on the cause of infection.
For simple cases of superficial folliculitis, your doctor may recommend a number of self-care measures, including:
- Good hygiene and handwashing;
- Antiseptic washes containing chlorhexidine, triclosan or povidone-iodine;
- Washes or lotions containing melaleuca (tea tree oil), and;
- Loose clothing.
There are a range of medications available for the treatment of deep folliculitis, including:
For types of folliculitis caused by bacteria (e.g. staphylococcal, pseudomonas and gram-negative folliculitis), your doctor may recommend an antibiotic cream, such as fusidic acid or mupirocin. If the folliculitis is severe or keeps coming back, you may be prescribed an antibiotic tablet, such as flucloxacillin or erythromycin.
If folliculitis is caused by a yeast infection (e.g. pityrosporum folliculitis), your doctor may prescribe a ketoconazole cream or shampoo, or tablets, such as fluconazole or itraconazole.
Alternatively, folliculitis caused by a viral infection may be treated with aciclovir, valaciclovir or famciclovir over a course of about 10 days.
For folliculitis caused by mites, your doctor may prescribe a permethrin cream or malathion lotion.
To treat a stye, your doctor may suggest applying a hot compress. In more severe cases, your doctor may remove lashes or make a small cut in the stye to drain it. If the infection appears to be spreading, an antibiotic ointment, such as chloramphenicol, may be prescribed.
Complications from folliculitis are rare, but can include:
- Spread of infection to surrounding hair follicles;
- Large, itchy patches on the skin (plaques);
- Permanent hair loss;
- Boils (furuncles);
- Groups of boils (carbuncles);
- Boils that keep coming back (furunculosis), and;
- Infection deep in the skin (cellulitis).
Treatment with antibiotics may be required if you develop boils, carbuncles or cellulitis.
In some situations, folliculitis may cause permanent hair loss or scarring, which can be embarrassing and distressing.
The outlook for folliculitis is generally very good, as most cases tend to clear without treatment.
General measures for preventing folliculitis involve keeping the skin clean, dry and free from factors that aggravate the condition. Some strategies could include:
- Changing your shaving habits - this may include taking breaks from shaving, using quality razor blades and shaving in the direction of hair growth;
- Wearing loose clothing;
- Keeping the skin moisturised, and;
- Not sharing personal items, such as towels or razors.
Using antiseptic washes on a regular basis is usually not recommended as they can dry your skin out. If you frequently experience folliculitis, you may wish to consider laser hair removal or depilatory products to remove unwanted hair.