Medical Disclaimer
The information on this page is for educational purposes only and is not intended to replace professional medical advice, diagnosis, or treatment.
Always seek the advice of your doctor or other qualified health professional with any questions you may have regarding a medical condition.
🚨Emergency? If you have severe symptoms, difficulty breathing, or think it's an emergency, call 000 immediately.
Finger Tendon Sheath Infection (Flexor Tenosynovitis)
Flexor tenosynovitis is a serious bacterial infection inside the protective sheath surrounding the flexor tendons in your finger (the tendons that bend your finger)—usually from puncture wounds, bites, or spread from nail infections—causing severe throbbing pain, swelling of the entire finger like a sausage, inability to straighten the finger due to pain, and requires emergency surgery within 24 hours to drain the infection and save the tendon, as delays can cause permanent tendon death and finger stiffness even with treatment.
📖What is Finger Tendon Sheath Infection (Flexor Tenosynovitis)?
Flexor tenosynovitis is a serious bacterial infection inside the protective sheath surrounding the flexor tendons in your finger (the tendons that bend your finger)—usually from puncture wounds, bites, or spread from nail infections—causing severe throbbing pain, swelling of the entire finger like a sausage, inability to straighten the finger due to pain, and requires emergency surgery within 24 hours to drain the infection and save the tendon, as delays can cause permanent tendon death and finger stiffness even with treatment.
🔬What Causes It?
- Puncture wound to palm or finger (thorn, splinter, needle stick, stepping on nail)
- Animal bite (cat bites particularly high risk - sharp teeth penetrate tendon sheath)
- Human bite (fight bite - punching someone in mouth, teeth penetrate knuckle)
- Spread from untreated paronychia (nail infection) or felon (fingertip infection)
- Penetrating laceration to finger or palm
- Rare: spread from wrist infection or hematogenous seeding in immunocompromised
⚠️Risk Factors
You may be at higher risk if:
- Diabetes (higher infection risk, faster progression, worse outcomes)
- Immunosuppression (chemotherapy, steroids, HIV, organ transplant)
- Penetrating hand injuries or bites
- IV drug use (injection into hand veins)
- Occupations with hand injury risk (farming, gardening, fishing, meat processing)
- Delayed treatment of minor finger infections
🛡️Prevention
- ✓Clean all finger puncture wounds immediately with soap and water
- ✓Seek medical care urgently for animal or human bites (antibiotics within 24 hours)
- ✓Treat paronychia (nail infections) and felons (fingertip infections) promptly before spread
- ✓Wear protective gloves during gardening, farming, handling fish/meat
- ✓Never ignore worsening finger pain after minor injury
- ✓If diabetic or immunosuppressed, be extra vigilant about hand wound care
- ✓Update tetanus vaccination if needed after penetrating injuries