What is paronychia?

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

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

What causes nail-fold infections?

• Bacteria tend to cause acute (sudden-onset) nail-fold infections which are painful.
• Candida, which is a yeast (a type of fungus), is another common cause. Candida nail-fold infections tend to develop slowly and cause chronic (persistent) infection. They do not cause pus to appear.
• Other microbes (germs), such as viruses and other fungi, are less common causes.

Why do nail-fold infections develop?

Many nail-fold infections 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:

• Water. You are more likely to develop a nail-fold infection if your hands are in water for long periods, particularly with detergents. Cleaners, bartenders, beauticians, dish washers, etc, are prone to nail-fold infections. Constant washing may damage the nail fold and allow infection to develop.
• Injury. For example, nail biting, poor manicure, damaged or diseased nails or nail folds, etc.
• Covering. For example, if you use gloves for long periods, or use artificial nails, it can cause a moist, airless condition around your fingernails. This is good for some germs to thrive and cause infection.

What is the treatment for nail-fold infections?

Bacterial infections

If your infection is caused by a bacterium then an antibiotic for seven days may be prescribed. Sometimes pus from a bacterial infection has to be drained by a very small cut if it collects next to the nail.

It may also help to soak the affected finger in warm salted water four times a day. Painkillers, such as paracetamol or ibuprofen, often work well to ease any pain.

If the antibiotic prescribed is not improving your infection after you have been taking it for a few days, you should see your doctor. Your doctor may take a swab of the infected area (to determine the actual bacteria causing your symptoms) and also change the antibiotic to a different one.

Candidal and fungal infections

These are usually treated with an antifungal cream. Treatment is usually needed for 3-6 months before the infection goes completely and a new healthy nail fold has formed.

Sometimes, a course of antifungal tablets or antifungal nail paint is needed for 6-12 months to clear the infection, particularly if the infection spreads to your nail in addition to your nail fold.

The following may help to prevent a recurrence of nail-fold infections:

• Do not bite your nails or pick at the skin next to nails.
• Keep your hands and feet dry as much as possible. Dry well after washing.
• Wear rubber gloves (preferably cotton-lined) if you work a lot with water.
• Do not wear gloves or artificial nails for long periods.

References

• Boils, carbuncles, folliculitis, paronychia and staphylococcal whitlow, Clinical Knowledge Summaries (2007)
• Vidimos A et al; Dermatological Manifestations of Paronychia, eMedicine, Jun 2010