Nail Infection (Paronychia) Facts
- Paronychia is the most common nail infection.
- Paronychia is usually caused by bacteria (Staphylococcus aureus).
- A chronic form of paronychia is often due to fungal infection.
What Is a Nail Infection (Paronychia)?
An infection that develops along the edge of the fingernail or toenail is called a paronychia (pear-ah-NIK-ee-ah). It is the most common hand infection and, if left untreated, can progress to a more severe infection of the entire finger or toe. Paronychia is distinguished from other infections such as onychomycosis and herpetic whitlow by its location and appearance.
What Causes a Nail Infection (Paronychia)?
Paronychias are most often caused by common skin bacteria (most commonly staphylococci bacteria) entering the skin around the nail that has been damaged by trauma, such as nail biting, finger sucking, dishwashing, or chemical irritants. Fungal infection also can be a cause of chronic paronychia and is considered particularly in people with the recurrent infection. Paronychia can be confused with herpetic whitlow, which can form tiny pustules on the finger and is caused by a virus, but is not typically located at the nail edge. Herpetic whitlow is not treated with an incision and drainage as can be a paronychia.
What Are Nail Infection (Paronychia) Risk Factors?
Risk factors include any trauma to the nail, nail trimming, or jobs where your nails and hands are exposed to water frequently or are exposed to solvents. Having diabetes makes you more prone to many infections, including paronychia.
What Are Nail Infection (Paronychia) Symptoms and Signs?
A paronychia may start as redness and swelling around the nail. It is most often very sore to the touch and, at times, may be a yellow-green color, indicating that a collection of pus has formed under the skin (called an abscess) of the toenail or fingernail.
The most common symptoms and signs are the following:
- Swelling around the fingernail or toenail
- Pus collection
- Pain and tenderness to touch
Ringworm is caused by a fungus.
When Should Someone Seek Medical Care for a Nail Infection (Paronychia)?
Call a health care professional if the redness extends beyond the skin around the nail or to the pad of the finger. This redness shows that the infection of the nail might be forming a more serious finger infection with pus formation of the deep tissues of the fingertip, called a felon.
Contact a health care professional if an abscess is forming. The condition requires drainage by a doctor. Opening (or incising) an abscess to drain the pus should not be attempted at home.
At the first sign of pus collection, seek medical attention for possible drainage. If one notices that the swelling and redness has extended down the finger or one is unable to move the joints of the affected finger, go to a hospital's emergency department immediately. This condition may or may not be associated with symptoms and signs such as fever or chills, indicating a serious infection.
What Health Care Professionals Diagnose and Treat Nail Infection (Paronychia)?
Primary care doctors will usually be able to diagnose and treat paronychia. Rarely, an abscess could get large enough that a surgical specialist (hand surgeon) would need to intervene.
How Do Health Professionals Diagnose a Nail Infection (Paronychia)?
A doctor will examine the finger and decide how severe the infection is and what treatment is needed.
Are There Home Remedies for a Nail Infection (Paronychia)?
Care at home includes warm soaks in warm water or a mixture of 50% warm water and 50% liquid antibacterial soap three to four times daily for about 15 minutes. This soaking should be done at the first sign of redness around the nail. Once any abscess is visible, you should see your doctor.
What Is the Medical Treatment for a Nail Infection (Paronychia)?
If an abscess (pus pocket) has formed, the recommended treatment is to drain the patient's abscess by doing an incision and drainage procedure.
- A doctor will most likely use a medication (such as lidocaine) to numb the entire finger first and then will open the abscess using a surgical knife (scalpel).
- Sometimes packing called a wick is placed in the abscess to allow it to continue to drain when one goes home and to keep it from closing up and reforming the abscess. The packing is usually left in for 24-48 hours.
- In extreme cases, the infection can move under the patient's fingernail and may need partial or complete nail removal. Antibiotic treatment are usually not necessary unless there is extensive infection spreading onto the digit.
- A doctor may or may not take a culture of the drainage to check for the type of bacteria involved in the infection.
- After a doctor has drained the paronychia, warm soaks are still recommended. Usually, medications such as antibiotics are only prescribed if the infection involves more of the finger than around the nail bed. Sometimes a topic antibiotic, such as Bacitracin, is applied. It is important to follow up with your doctor in 24-48 hours after treatment to be sure that the infection is healing properly.
What Follow-up Is Needed After Treatment of a Nail Infection (Paronychia)?
- Warm soaks
- Follow-up appointment for removal of the wick (if placed)
Is It Possible to Prevent a Nail Infection (Paronychia)?
- Avoid fingernail biting.
- Wear rubber gloves if engaging in frequent hand washing or moisture-type exposure.
- Control chronic illnesses, such as diabetes.
- Wash hands frequently, especially if working in dirt, carpentry, or any job where the hands get soiled and have the potential for cuts and scrapes.
What Is the Prognosis of a Nail Infection (Paronychia)?
If treated early, the prognosis is very good. Some paronychias become chronic and recurring infections. In those situations, a fungal cause of the infection is particularly considered.
Nail Infection (Paronychia) Pictures
A moderate paronychia. Swelling and redness around the edge of the nail is caused by a large pus collection under the skin. Another view of the same paronychia. The majority of the swelling and redness can be seen on the right side of this picture. A scalpel (knife) is inserted under the skin at the edge of nail to open the pus pocket and drain it to relieve the pressure and treat the infection. A closer view of the scalpel used to open the infected area. The doctor pushes on the swollen area to get the pus out after the incision was made with the scalpel.
Rosacea, Acne, Shingles: Common Adult Skin Diseases
Reviewed on 10/11/2018
Biesbroeck, L.K., and P. Fleckman. "Nail Disease for the Primary Care Provider."
Med Clin North Am 99.6 Nov. 2015: 1213-1226.