Paronychia

What is paronychia?

Paronychia is an infection of the skin just next to a nail (the nail fold). The infected nail fold looks swollen, red and feels tender.

There may also be a small collection of pus in the swelling. The nail itself may become infected or damaged if a paronychia is left untreated.

What are the symptoms of paronychia?

There is a swelling next to the fingernail, in the skin around the nail bed. The area is often hot, red and tender. Pus may be visible. There may be an associated fever although this is not common.

What causes paronychia?

• Bacteria. These tend to cause a sudden-onset (acute) paronychia which is painful. A bacterium called Staphylococcus aureus, which usually lives harmlessly on our skin, is most often the cause.

• Candida. This is a yeast (a type of fungus) and is another common cause. A paronychia due to candida tends to develop more slowly and causes a more persistent (chronic) infection. Pus does not appear in fungal paronychia.

• Other microbes. These include viruses and other fungi. They are less common.

Many instances of paronychia occur for no apparent reason. However, the following can increase the risk of bacteria and other germs getting into the nail-fold skin and causing infection:

Prolonged exposure to water

Paronychia is more likely to develop if the hands are in water for long periods, particularly with detergents. Constant washing may damage the nail fold and allow infection to develop. The following are examples of people who might be more prone to paronychia due to their job:

• Cleaners.

• Bartenders.

• Fishermen.

• Beauticians.

• People who wash dishes frequently.

• Dairy farmers.

• Healthcare workers.

Injury

A break in the skin allows the bacteria which are already living on the skin to get inside. Examples which make paronychia more likely include:

• Nail biting

• Picking at the skin around the nails.

• Getting splinters in the skin around the nails.

• Poor manicure technique - for example, pushing the cuticles back too far with a hard instrument.

• Damaged or diseased nails or nail folds - for example, from skin conditions such as eczema or contact dermatitis.

• Ingrowing toenails - the nail grows into the skin, breaking it.

Covering your hands

People using gloves for long periods, or who wear artificial nails, can develop a moist, airless condition around their fingernails. This can cause paronychia, particularly fungal paronychia.

Types of paronychia

• Acute - these are usually caused by bacteria. They usually develop quickly and cause pain, swelling, redness and tenderness. They may also cause fever.

• Chronic - these are usually caused by fungal infections. They usually develop more slowly. A paronychia is considered chronic when it has lasted for more than 6 weeks.

How to treat paronychia

Prevention is always better than cure. However, if a paronychia develops the following treatments can help:

Warm bathing and painkillers

It often helps to soak the infected finger in salted warm water four times a day. Painkillers, such as paracetamol or ibuprofen, often work well to ease any pain. This can be tried before seeking further advice as many mild cases of paronychia get better without needing antibiotics.

Antibiotics

If the infection is caused by bacteria, then a healthcare worker may prescribe an oral antibiotic. Antibiotics commonly used for paronychia include flucloxacillin or erythromycin. In a more minor infection, an antibiotic cream may be enough - for example, fusidic acid cream.

If the antibiotic prescribed is not improving the paronychia after a few days, further medical advice should be sought. The antibiotic may need to be changed to a different one.

It is also important to remember than antibiotics can make a fungal infection worse. Antibiotics may therefore not be prescribed if the infection is thought to be possibly due to a fungus.

Draining the pus out

Occasionally, if a lot of pus has collected, and the finger or toe is very swollen, the pus may need to be drained. A small cut is made to allow the pus to come out. This would usually be done in an emergency department or an urgent care centre.

Treatment for paronychia which lasts more than six weeks

If the problem has persisted for six weeks or more, it is called a chronic paronychia. If this is the case there may be an underlying skin condition. In other cases, there can be an infection with a yeast or fungus. This is particularly common in those people mentioned above who have their hands in water a lot.

Treatment includes:

• Keeping the hands warm and dry.

• Avoiding anything which might irritate the skin, such as soaps and detergents.

• Avoiding injury, e.g. avoid manicures, finger sucking, nail biting etc.

• Avoiding false nails.

• Wearing very comfortable shoes if the affected nail is a toenail, to avoid any pressure on it.

• Treating any underlying skin condition.

• Steroid creams, such as hydrocortisone or betamethasone.

• Antifungal creams such as clotrimazole, miconazole or terbinafine.

• Antifungal tablets such as terbinafine or itraconazole.

• Rarely - an operation to open up the infected area and keep it open and let it drain and heal over time.

How to prevent paronychia

The following may help in preventing paronychia:

• Do not bite fingernails.

• Do not pick at the skin next to nails.

• Keep hands and feet dry as much as possible. Dry well after washing.

• Wear rubber gloves (preferably cotton-lined) if working a lot with water.

• Do not wear gloves or artificial nails for long periods.

• Cutting toenails straight across to avoid ingrowing toenails which make paronychia more likely to occur.

Complications of paronychia

It is rare for a paronychia to develop complications but occasionally the infection can affect deeper structures such as the tendons or bones, leading to an osteomyelitis or tenosynovitis. This is very unusual and usually only seen where the paronychia has been neglected for some time or in people with a severely weakened immune system. Sometimes the nail can develop signs of damage after a paronychia - for example misshaping or ridging - and this can last for a long time or even be permanent if the nail-bed has been damaged.

When should I see a doctor?

Medical advice should be sought when a paronychia develops that is not settling within a few days of conservative treatment, such as regular soaking in salt water and otherwise keeping the area dry and protected. Medical advice should also be sought earlier than this if the paronychia is getting worse.