Treatment of Subungual Hematoma
The most effective treatment for a subungual hematoma is prompt nail trephination to evacuate the blood collection, which provides immediate pain relief and prevents further damage to the nail bed. 1
Understanding Subungual Hematoma
Subungual hematoma is a collection of blood under the nail plate that results from:
- Direct trauma to the fingernail or toenail
- Repetitive shear forces (common in athletes)
- Crush injuries
The trapped blood creates pressure between the nail plate and nail bed, causing significant pain and discomfort.
Diagnosis and Assessment
Before treatment:
- Assess the extent of the hematoma (percentage of nail affected)
- Obtain radiographs to rule out underlying distal phalanx fractures, as they are commonly associated with subungual hematomas 1, 2
- Evaluate for nail bed lacerations or other injuries that may require additional treatment
Treatment Options
1. Nail Trephination (First-line Treatment)
Several effective methods for nail trephination exist:
- Electrocautery device: Creates a hole through the nail plate without damaging the nail bed; provides immediate pain relief 1
- Extra-fine insulin syringe (29-gauge):
- Particularly effective for smaller hematomas and difficult-to-access nails (2nd, 3rd, 4th toes)
- Insert needle close to nail plate and drain blood from hyponychium
- Fast, simple, and well-tolerated by patients 3
- Controlled nail drill:
- Designed to penetrate nail plate without breaching nail bed
- Provides substantial pain relief within hours 4
- Other methods: Paper clip, heated paperclip, or specialized trephination devices
2. Post-Trephination Care
- Apply antiseptic solution after drainage
- Keep the area clean and dry
- Monitor for signs of infection
- Follow up within 1-2 weeks to ensure proper healing 5
Important Clinical Considerations
- Pain Relief: Patients typically experience immediate pain relief after successful drainage 1, 6
- Nail Removal Not Necessary: For simple subungual hematomas, regardless of size, nail removal with suture repair of the nail bed is unnecessary 1
- Regrowth Timeline: Average time for complete nail regrowth is approximately 4 months 1
- Potential Complications: Patients should be warned about possible onycholysis, transient or permanent nail deformity, and infection, even with optimal treatment 2
- Special Populations: Diabetic and immunocompromised patients require more vigilant monitoring due to increased infection risk 5
When to Consider Additional Treatment
- Large hematomas with significant nail bed injury
- Presence of distal phalanx fractures
- Signs of infection
- Failure to improve with initial trephination
Follow-Up Care
- Return for evaluation if signs of infection develop (increased pain, redness, swelling, discharge)
- Monitor nail growth for deformities
- Complete nail regrowth may take 4-6 months
Nail trephination for subungual hematoma is a quick, effective procedure with minimal risk when performed properly, allowing patients to resume normal activities with significant pain relief.