Draining Subungual Hematoma: Benefits vs Risks
Draining a subungual hematoma provides immediate pain relief with minimal risk of complications and should be performed when pain is significant or the hematoma covers more than 25% of the nail.
Benefits of Draining Subungual Hematoma
- Immediate pain relief: The primary benefit is rapid reduction in pain by relieving pressure under the nail 1, 2, 3
- Prevention of nail loss: Timely drainage may help preserve the nail plate by reducing pressure that can separate the nail from the nail bed
- Improved healing: Evacuation of blood allows better assessment of underlying injuries and promotes faster healing
- Patient comfort: Simple procedure that provides significant improvement in patient comfort 3
Risks and Complications
- Infection: Minimal risk when performed with proper sterile technique
- Nail bed injury: Potential damage if trephination penetrates too deeply 3
- Incomplete drainage: May require repeat procedure if blood reaccumulates
- Nail deformity: Rare but possible if nail matrix is damaged
- Fire risk: When using electrocautery with acrylic nails (41.5% ignition rate) 4
Technique Options and Considerations
1. Needle Trephination
- Using a 29-gauge insulin syringe needle is particularly effective for smaller hematomas, especially on the 2nd, 3rd, and 4th toenails 1
- Insert needle very close to nail plate to minimize pain
- Drain blood from hyponychium under nail plate
2. Controlled Nail Trephination
- Using a specially designed drill that penetrates nail plate without breaching nail bed 3
- Quick and convenient method with minimal discomfort and risk
3. Electrocautery
- Effective for most cases but contraindicated with acrylic nails due to 41.5% risk of ignition 4
- Should be avoided in patients with artificial nail products
4. Heated Paper Clip
- Traditional method, widely available
- Less precise than other methods
Decision Algorithm for Management
Assess hematoma size and pain level:
- Small hematoma (<25% of nail) with minimal pain → Conservative management
- Large hematoma (>25% of nail) or significant pain → Drainage indicated
Check for contraindications:
- Presence of acrylic nails → Avoid electrocautery (use needle method instead)
- Underlying nail bed laceration → Consider nail removal and repair
- Immunocompromised state → Extra caution with sterile technique
Select appropriate technique based on available equipment and location:
- Fingernails → Any method appropriate
- Toenails (especially 2nd-4th) → 29-gauge insulin syringe preferred 1
Post-procedure care:
- Keep area clean and dry
- Monitor for signs of infection
- Apply antibiotic ointment if needed
Common Pitfalls to Avoid
- Inadequate pain control: Ensure proper anesthesia before procedure
- Penetrating too deeply: Risk of nail bed injury
- Using electrocautery with acrylic nails: High risk of ignition (41.5%) 4
- Failure to recognize associated fractures: Consider X-ray for severe crush injuries
- Delayed treatment: Can lead to increased pain and potential nail loss
The evidence strongly supports that when performed correctly, draining a subungual hematoma is a safe, effective procedure that provides significant pain relief with minimal complications 2, 3.