How to drain a finger paronychia

Improve your in-clinic patient care with this article on draining a finger paronychia, a common finger infection.
Last update21st Apr 2024

What is a finger paronychia?

A paronychia is an infection of the nail root of the fingers or toes. It’s a very common infection and is caused by the introduction of bacteria under the cuticle. This is often from people chewing or ripping a hangnail with their teeth, and is also seen in barbers.

In a wound culture, Staphylococcus is the most common bacteria. But, you can have any kind of bacteria (such as anaerobes) from the mouth.

Physical signs of a finger paronychia

Patients usually seek help after a few days of increasing swelling and pain at the base of a nail. The area is sensitive and pressure from the building pus is painful.

If the infection continues, it can extend to the pulp of the finger and cause a felon, or deep tissue abscess. This requires aggressive procedures and can even lead to loss of function or amputation.

Figure 1. Physical signs of a finger paronychia include swelling at the base of the nail, sensitivity to touch, pain, and pressure from pus build-up. A deep tissue abscess, or felon, can develop if the infection continues.

How do you treat paronychia?

If the infection is caught early when the nail base is a little swollen and red, you can prescribe frequent warm soaks (at least once every two hours), and a short course of antibiotics (e.g., cephalexin). An established infection and pus collection require incision and drainage.

Figure 2. Early paronychia infections can be treated with frequent warm soaks and antibiotics. Established infections require incision and drainage.

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The tools you need to drain a finger paronychia

The first step when performing the incision and drainage technique is to collect the necessary medication and tools:

  • Sterilizing solution
  • Ice water
  • #11 scalpel
Figure 3. Tools for a finger paronychia include sterilizing solution, ice water, and #11 scalpel.

How to drain a finger paronychia

This step-by-step procedure ensures a safe, clean, and (relatively) painless abscess drainage:

  1. Place the patient’s finger in a cup of ice water until they can’t stand it anymore to numb the finger. This method is fast, painless, and softens the cuticle. Alternatively, you can perform a digital nerve block.
  2. When the finger is numb, clean the cuticle with the sterilizing solution.
  3. Stab under the skin parallel to the nail, using your #11 blade.
  4. You will immediately see pus come out.
Figure 4. Procedure for draining a finger paronychia. 1) Numb the finger with ice water or a digital nerve block. 2) Clean the cuticle with sterilizing solution. 3) Stab under the skin parallel to the nail with the #11 blade. 4) Pus will escape from the incision.

Post-procedure care for a finger paronychia

Have your patient soak their finger in warm water every two hours for the next two days. Antibiotics are not needed for minor cases of paronychia, but use your judgment depending on the patient’s risk factors.

Figure 5. After draining a finger paronychia, instruct your patient to soak their finger in warm water every two hours for the next two days.

Excellent job! You’re well on your way to mastering the treatment of a finger paronychia.

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About the author

Siamak Moayedi, MD
Professor and Director of Medical Student Education, University of Maryland and Course Director, Essential and Critical Procedures, Emergency Medicine.
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ACCME accredited, UEMS accredited, Comenius EduMedia Siegel 2017, BMA Highly recommended