ConditionSkin, hair & nails
Felon (Fingertip Abscess)
A felon is a bacterial abscess in the fleshy pad of a fingertip. It usually follows a puncture, splinter or cut, and is most often caused by Staphylococcus aureus. Because the fingertip pad is divided into tight compartments, pus builds up pressure quickly, causing intense, throbbing pain and a tense, red, swollen fingertip. A felon needs prompt medical care: most need surgical drainage plus antibiotics, because untreated pressure can damage the bone, tendons and skin of the fingertip.
Also called: Fingertip abscess, pulp space infection, finger pulp abscess, digital pulp abscess
At a glance
- What it is
- An abscess in the closed compartments of the fingertip pad.
- Cause
- Bacteria, usually Staphylococcus aureus (including MRSA), entering through a puncture, splinter or cut.
- Symptoms
- Severe throbbing pain, tense swelling and redness of the fingertip pad, sometimes a visible pus pocket.
- Diagnosis
- Examination; X-ray if bone infection or a foreign body is possible.
- Treatment
- Incision and drainage under a local anesthetic block, antibiotics, and wound care.
When to get help
Call 911 or go to the ER
- Red streaks spreading up the hand or arm with fever, chills or feeling very unwell
See a doctor within a day or two
- A tense, swollen, red, intensely painful fingertip pad, especially after a puncture or splinter (same-day care)
- Swelling spreading along the whole finger, with the finger held bent and pain on straightening it (possible flexor tendon sheath infection)
- A fingertip infection in someone with diabetes or a weakened immune system
Book a routine appointment
- A fingertip that remains painful or swollen weeks after treatment
Usually safe to manage at home
- A small splinter or puncture with mild redness: wash, remove the splinter and keep it clean, but seek care if pain and swelling increase
What happens in a felon
The pad of the fingertip is made of fat held in place by many small fibrous walls (septa) running from the skin to the bone. These create tight compartments. When bacteria get in and form pus, the compartments cannot expand, so pressure rises sharply. That causes the severe, throbbing pain typical of a felon and, if untreated, can cut off blood flow and lead to tissue death, bone infection or spread into the tendon sheath.
Causes and risk factors
- puncture wounds: splinters, thorns, glass, needles and finger-prick blood glucose testing
- cuts to the fingertip
- spread from a paronychia (nail fold infection)
- diabetes, weakened immunity and poor circulation
The thumb and index finger are most often affected. The bacteria are usually Staphylococcus aureus; MRSA is common in many areas. Streptococci and gram-negative bacteria are less common.
Symptoms
- rapid onset of intense, throbbing pain in the fingertip pad
- tense, firm swelling of the pad that does not extend past the last joint crease
- redness and warmth
- a visible pocket of pus under the skin in some cases
- sometimes fever and swollen lymph nodes at the elbow or armpit
Felon vs other finger infections
| Infection | Location | Key features |
|---|---|---|
| Felon | Fingertip pad | Tense, very painful pad swelling |
| Paronychia | Skin fold around the nail | Red, swollen nail edge, often with pus |
| Herpetic whitlow | Fingertip | Clusters of small fluid-filled blisters; caused by the herpes virus; should not be cut open |
| Flexor tenosynovitis | Tendon sheath along the finger | Whole finger swollen, held bent, pain on straightening; surgical emergency |
| Cellulitis | Skin | Spreading redness without a pus pocket |
Telling a felon from herpetic whitlow is important, because cutting into a herpes infection can spread it and cause a secondary bacterial infection.
Diagnosis
A doctor examines the finger, presses gently to find the point of maximum tenderness or a soft pus pocket, and checks for tendon sheath involvement. An X-ray checks for a retained foreign body or bone infection (osteomyelitis). Pus is sent for culture to guide antibiotics.
Treatment
Early infection
If seen very early, before pus forms, a felon may settle with antibiotics, warm soaks, elevation and close review within 24 to 48 hours.
Incision and drainage
Most felons need drainage:
- A digital block numbs the finger.
- The doctor makes an incision, usually over the point of maximum swelling, avoiding the sensitive pad when possible and the nerves along the sides.
- Pus is drained and the compartments opened, and the wound is rinsed.
- A small packing or drain may be placed.
Antibiotics
Antibiotics cover staph and strep bacteria, including MRSA where it is common, for example trimethoprim-sulfamethoxazole, clindamycin or doxycycline, sometimes combined with cephalexin. Results of the pus culture may change the choice.
Aftercare
- keep the hand raised above heart level
- warm water soaks several times a day after the first day or two, as advised
- change dressings as instructed
- return within 48 hours, or sooner if pain, swelling or redness worsen
- check tetanus vaccination
Complications
- bone infection of the fingertip
- infection spreading to the tendon sheath or joint
- death of fingertip skin and tissue
- a numb, scarred or misshapen fingertip pad
Prevention
- remove splinters promptly and clean puncture wounds well
- wear gloves for gardening and work with sharp materials
- rotate finger-prick sites if you test your blood sugar
- treat nail fold infections early
Frequently asked questions
What is a felon on the finger?
A felon is a bacterial abscess in the fleshy pad of the fingertip, usually after a splinter, puncture or cut. It causes intense, throbbing pain and tense swelling because pus is trapped in small, tight compartments.
How is a felon treated?
Most felons are treated by numbing the finger and draining the pus through a small incision, followed by antibiotics, elevation and soaks. Very early infections may respond to antibiotics alone with close follow-up.
What is the difference between a felon and a paronychia?
A paronychia affects the skin fold around the nail, causing redness and swelling at the nail edge. A felon affects the pad of the fingertip, causing tense, very painful swelling of the pad. A paronychia can spread to cause a felon.
Can a felon go away on its own?
It is unlikely once pus has formed. The tight compartments of the fingertip keep the infection trapped, and untreated felons can damage the bone and tissues. See a doctor promptly for a painful, swollen fingertip.
Sources
This guide was written from current patient and clinical guidance, including:
- American Society for Surgery of the Hand: Hand Infections
- American Academy of Family Physicians: Acute and Chronic Paronychia and fingertip infections (American Family Physician)
- MedlinePlus: Skin abscess
- StatPearls (NCBI Bookshelf): Felon
- Infectious Diseases Society of America: Practice Guidelines for the Diagnosis and Management of Skin and Soft Tissue Infections (2014)