A paronychia is a type of infection that is easily diagnosed because it affects the edge of the nail on a finger or toe. It is the most widespread of all hand infections and is usually harmless. However, if it is ignored for a long time, it can eventually expand to the entire finger. The unique location of paronychia sets it apart from onychomycosis, herpetic whitlow and other hand infections.

Doctors divide paronychia in acute and chronic varieties. Acute paronychia is the most virulent type of infection. It starts without warning around finger or toe nails, usually after the location was injured in some way. It causes a lot of pain, as well as redness, swelling and a warm sensation. In most cases, the infection starts after bacteria use the local injury to infiltrate the skin. It is often caused by improper manicuring, especially if the thin skin that covers the edge of the nail (known as the cuticle) is cut. Many bad habits can also trigger infections. These include sucking your own fingers, biting the nails or the skin around them, as well as picking the skin in the area.

By contrast, chronic paronychia has a much slower progress. The symptoms are almost identical, with redness, swelling and mild pain that become worse in time. It is common for several fingers of one hand to be infected at the same time and it is caused by Candida or other species of yeast. Workers who perform certain jobs have a higher risk to develop this condition, if their hands are constantly soaked or exposed to various chemical solvents. Examples include house cleaning, bartending, dishwashing, hairdressing, janitorial work, dentistry, nursing or food service jobs. People who suffer from diabetes are also more vulnerable to such infections.

What causes paronychia?

The most common pathogens that cause paronychia are staphylococci and other types of bacteria that inhabit the skin. If the area surrounding a nail is injured in some way, these germs can enter the skin. This can happen during dishwashing, due to nail biting or after contact with strong chemical agents. Chronic paronychia can also be started by fungi and is usually the cause of recurring infections. This condition is sometimes confused with herpetic whitlow, which is a viral disease. While herpetic whitlow can form small pustules on fingers, there are rarely found on nail edges and can't be incised and drained.

Constant exposure to water or chemicals, such as cleaning agents, is another common cause of chronic paronychia. Candida and the various types of bacteria like to grow in the water, so the moisture allows them to multiply. The chronic condition commonly affects people who have wet hands for long periods of time, like dishwashers, bartenders, housecleaners or employees of the food industry. Irritant dermatitis also increases the risk of chronic paronychia. The red, itchy and irritated skin allows the pathogens to penetrate more easily.

What are the symptoms of paronychia?

Acute and chronic paronychia have almost identical symptoms and the main differences are the duration and the rate of progress of the condition. Acute paronychia starts suddenly and develops very fast but it also has a short duration. Chronic infections can last several weeks and develop slowly. Otherwise, the symptoms are very similar.

These include the inflammation and redness of skin around the nail, tenderness or pain in the area and the appearance of blisters filled with pus. In more severe cases, the nail changes its normal shape or color and it can even completely detach from the nail bed.

Acute outbreaks of this disease lead to severe pain, besides the usual symptoms that are redness, swelling and the warm sensation around the nail. It often affects a single nail and some pus can accumulate under the skin or under the nail.

Chronic paronychia has the same symptoms as the acute version, but these tend to be milder. Instead of strong pain, the nail area is just tender, with redness and swelling. The skin around the nail becomes soft, while the cuticle is missing. This type of disease can affect more than one nail on the same hand.

Treatment options

Infections that are not too severe can effectively be treated with home remedies. If the infected area is filled with pus, you can simply soak the finger in warm water several times every day and then dry it very well. This speeds up the rate of healing and the infection can drain without any treatment. If home treatment becomes ineffective or the infection is very strong, your doctor will prescribe an antibiotic.

A faster way of healing is to drain the fluids in the blisters and abscesses, especially if they cause serious pain. This is a medical procedure that should only be performed by a doctor, don't try it yourself. Sometimes, a sample of pus can be collected in order to test it and find out the exact pathogen that caused the infection.

Even if it causes milder symptoms, the chronic condition is a lot harder to cure and home treatments will probably fail. The most likely cause is a fungus, you will have to make sure the area remains dry and use prescription antifungal medicine. Local anti-inflammatory drugs can also help in some cases. Surgical removal of a part of the nail is a possible option in very severe infections.