A nail infection, or paronychia, is an infection of the skin that surrounds a fingernail. The infected tissue can be tender and painful with swelling. Paronychia is considered acute if it lasts less than 6 weeks, or chronic if it lasts longer.
Staphylococcus aureus and Streptococcus pyogenes bacteria are the most common culprits in acute paronychia but there are other causes as well.
Chronic paronychia tends to be caused by repeated inflammation from irritants, moisture or allergens, and may involve multiple nails. Infection with fungus and bacteria may also occur. Paronychia may be seen in people with eczema or psoriasis, or as a side effect of a medication.
Any trauma to the nail or skin surrounding the nail such as aggressively trimming or manicuring your nails can create a way for bacteria to enter and cause an infection. People who have jobs that frequently expose their hands to water or irritants such as chemicals used in washing dishes are at an increased risk of chronic paronychia. Persons with diabetes or diseases that compromise the immune system are more likely to develop infections.
With acute paronychia, a crack in the nail fold or trauma to the nail is usually seen first. Then your finger and nail fold may become red, tender and swollen.
In contrast, chronic paronychia is diagnosed after 6 weeks of inflammation, and may affect several nails and may cause the nail to appear deformed.
Most often, the diagnosis is made by the appearance of the nail and the skin around it. Your doctor will decide if a culture (taking a bit of tissue from the area for lab examination) is necessary.
Paronychia will be diagnosed by your doctor. The treatment will be based on the severity of inflammation and infection and may include drainage, topical or oral medications.
Taking proper care of your nails will greatly reduce the chance of an infection. Do not chew on your nails or pick at the skin around them. Do not trim the cuticles (the skin at the base of the nail). Disrupting the nail or cuticle will create an entry for bacteria and fungi. In general, you should keep your hands away from chronic water exposure and avoid any irritants or allergens from coming in contact with your skin.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 12/28/2017