Skin Infection Around Fingernails and Toenails

In This Article
Table of Contents

Paronychia is an infection of the layer of skin surrounding the nail (known as the perionychium). It is the most common hand infection in the United States and is seen frequently in children as a result of nail biting and finger sucking.

The condition can be classified as either acute (rapidly progressing with a short duration) or chronic (ongoing and persistent), depending on the amount of time the infection has been present.

This photo contains content that some people may find graphic or disturbing.

Paronychia: swollen finger with fingernail bed inflammation
Paronychia hand infection. kckate16 / Getty Images 

Causes

Both acute and chronic paronychia start with the penetration of the outer layer of skin called the epidermis.

Acute paronychia is usually the result of a direct trauma to the skin, such as a cut, hangnail, or ingrown nail. Bacteria are the most common cause of the infection, predominately Staphylococcus aureus, but also certain strains of the Streptococcus and Pseudomonas bacteria.

Meanwhile, chronic paronychia is most frequently caused by repeated exposure to water-containing detergents, alkali, or other irritants. It can lead to swelling and gradual deterioration of the epidermal layer. Most chronic infections are caused by the fungus Candida albicans (yeast) and other fungal agents.

Appearance

Acute paronychia starts as a red, warm, painful swelling of the skin around the nail. Over time, accumulation of pus may separates the skin from the nail. In more severe cases, the lymph nodes in your elbow and armpit may swell and your nail may become discolored.

In chronic paronychia, redness and tenderness are usually less noticeable. The skin around the nail often looks baggy, and the cuticle may separate from the nail bed. The nail often becomes thickened and discolored with pronounced horizontal grooves on the surface. Green discoloration can occur in cases of Pseudomonas infection.

Diagnosis

Acute paronychia is typically diagnosed based on a review of the clinical symptoms. If pus is oozing, your doctor may make an incision to drain it.

In severe cases, they may culture bacteria from the drained pus to make a definitive diagnosis. This usually isn't necessary because the bacteria is usually Staphylococcus or Streptococcus type, both of which are treated similarly.

Chronic paronychia tends to be more difficult to diagnose. A potassium hydroxide (KOH) test, using a smear is extracted from the nail fold, sometimes confirms a fungal infection. If pus is involved, a culture can confirm the presence of fungus or other, less common infectious agents.

Treatment

For an acute infection, soaking the nail in warm water three to four times a day can promote drainage and relieve some of the pain. Some doctors suggest an acetic acid soak, using one part warm water and one part vinegar.

If you have pus or an abscess, the infection may need to be incised and drained. In some cases, a portion of the nail may need to be removed.

Bacteria-associated paronychia is most commonly treated with antibiotics such as cephalexin or dicloxacillin. Topical antibiotics or anti-bacterial ointments are not considered an effective treatment.

Chronic paronychia is typically be treated with a topical antifungal medication such as ketoconazole cream. In addition, a mild topical steroid may be used to help reduce inflammation. (Steroids should never be used on their own as they don't treat the underlying infection.)

Some people tend to have more extensive paronychial infections and may need to be treated with a prolonged course of antibiotics, including those with:

  • A compromised immune system, such as from HIV
  • Long-term corticosteroid use
  • Diabetes
  • Autoimmune disease, including psoriasis and lupus
  • Poor circulation in the arms or legs

Prevention

You have several options for reducing the risk or severity of a paronychial infection.

  • Do not bite nails or trim them too closely.
  • Never bite or cut cuticles.
  • Ensure that your manicurist always uses sterile instruments.
  • Try not to suck fingers.
  • Wear waterproof gloves when immersing your hands in detergents, cleaning fluids, or strong chemicals.
  • Avoid soaking your hands in water for prolonged periods of time (or, again, use waterproof gloves).
  • For cuts and scrapes, wash your hands with antibacterial cleanser and bandage, if necessary.
  • Dry your feet thoroughly if they are immersed for long periods of time in unclean water or water containing detergent or chemicals.
  • Change your socks regularly and use an over-the-counter foot powder if your feet are prone to sweatiness or excessive moisture.
Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Shafritz, A. and Coppage, J. Acute and chronic paronychia of the hand. Journal of the American Academy of Orthopaedic Surgeons. March 2014;22(3):165-178. doi:10.5435/JAAOS-22-03-165