Management of Subungual Hematoma
For a painful subungual hematoma, immediate nail trephination (drainage) should be performed to relieve pain and prevent nail bed damage, using either a heated cautery device, a specialized drill, or a fine-gauge needle depending on availability and hematoma characteristics. 1, 2, 3
Initial Assessment
- Obtain radiographs of the affected digit to rule out distal phalangeal fracture, which occurs with high frequency in association with subungual hematomas 4
- Assess the size and location of the hematoma—smaller hematomas of the second, third, and fourth toenails may be particularly amenable to needle drainage 2
- Evaluate for signs of nail bed laceration or significant nail plate disruption that might require more extensive surgical intervention 4
Drainage Technique Selection
Three validated approaches exist for trephination:
Hand-Held Cautery (Preferred Method)
- Use a heated cautery device to burn a precise, small hole through the nail plate, which is cost-effective and allows controlled penetration without breaching the nail bed 3
- The high temperature and fine tip provide painless, precise drainage 3
- This method decreases likelihood of unnecessary delay in nail regrowth and secondary dystrophy from matrix pressure 3
Controlled Drill Trephination
- Employ a uniquely designed drill that penetrates the nail plate without breaching the nail bed for larger hematomas 1
- This technique provides quick drainage with minimal discomfort and minimal risk 1
Fine-Gauge Needle Aspiration
- Use a 29-gauge extra-fine insulin syringe inserted very close to the nail plate to minimize pain 2
- Drain blood from the hyponychium under the nail plate 2
- This technique is particularly successful for smaller subungual hematomas of the second, third, and fourth toenails where traditional trephining is more difficult 2
Post-Procedure Management
- Expect substantial pain relief within 8 hours of drainage 1
- Monitor for potential complications including onycholysis, transient or permanent nail deformity, and infection 4
- Avoid needle aspiration of hematomas in other anatomic locations (such as surgical pockets) due to risk of introducing skin flora and subsequent infection 5
Critical Pitfalls
- Do not delay drainage in symptomatic patients, as accumulated blood under the nail causes extreme discomfort from pressure and can damage the nail matrix 1, 3
- Always obtain radiographs before drainage due to the high incidence of associated distal phalangeal fractures 4
- Warn patients that despite optimal treatment, nail deformities and other complications remain possible 4