Management of Subungual Hematoma in a Healthy Adult
Immediate Treatment Recommendation
Perform nail trephination immediately to evacuate the hematoma and relieve pain, as this is the standard of care for painful subungual hematomas presenting within 48-72 hours of injury. 1
Clinical Assessment Before Intervention
Before proceeding with trephination, evaluate for:
- Extent of nail involvement: Hematomas covering approximately 50% of the nail plate typically cause significant pain and warrant drainage 1
- Presence of acrylic nails: If present, avoid electrocautery trephination due to 41.5% ignition risk; use alternative methods 2
- Signs of nail bed laceration: Severe trauma may require nail removal and nail bed repair rather than simple trephination 3
- Timing of presentation: Patients presenting within 48-72 hours are ideal candidates for drainage 1
Trephination Technique Options
Preferred Methods (in order of recommendation):
1. Hand-held electrocautery (if no acrylic nails present):
- Use a fine-tip cautery unit to burn a precise hole through the nail plate 4
- This method is painless, cost-effective, and allows controlled penetration without breaching the nail bed 5, 4
- The high temperature creates a clean opening for blood evacuation 4
2. Extra-fine insulin syringe needle (29-gauge):
- Insert the needle very close to the nail plate at the hyponychium (distal nail edge) to minimize pain 6
- Drain blood from under the nail plate using this approach 6
- Particularly effective for smaller hematomas of the second, third, and fourth toenails where trephining is more difficult 6
3. Controlled drill trephination:
- Use a uniquely designed drill that penetrates the nail plate without breaching the nail bed 5
- Provides quick evacuation with minimal discomfort and minimal risk 5
Post-Procedure Care
After successful drainage:
- Apply daily topical emollients to the periungual folds and nail plate to maintain hydration 7, 8
- Keep the area clean and dry using gentle water-based cleansers 8
- Monitor for secondary bacterial infection: If green or black discoloration develops (suggesting Pseudomonas), apply topical povidone-iodine 2% twice daily 7, 8
- Watch for paronychia (nail fold swelling, erythema, tenderness) and treat with appropriate antimicrobials if it develops 8
- Advise protective footwear: Use well-fitting shoes with adequate toe-box space and cotton socks to minimize friction 8
Indications for Nail Removal Rather Than Simple Trephination
Consider partial or total nail avulsion if:
- Painful subungual abscess is suspected in addition to the hematoma 3
- Severe nail bed laceration is present requiring repair 3
- Grade 2 or higher injury with intolerable pain despite trephination 3
When nail removal is performed, the nail bed must be cleaned and cultured, and any infection should be promptly treated with appropriate topical/oral antibiotics and antiseptics 3
Expected Healing Timeline and Follow-Up
- Complete nail regeneration may require 3-6 months, depending on the extent of injury 8
- Recurrent bleeding can occur within the first 2 weeks post-injury, particularly in patients with bleeding disorders 1
- Refer to a specialist if significant paronychia develops, persistent abnormal nail growth occurs after 3-4 months, or ongoing nail dystrophy suggests underlying dermatologic conditions 8
Critical Pitfalls to Avoid
- Do not use electrocautery on acrylic nails: The 41.5% ignition rate poses significant burn risk 2
- Do not delay treatment: Most cases in the literature presented with a 48-72 hour delay, which is suboptimal; immediate drainage provides better pain relief 1
- Do not assume fungal infection: If the nail becomes thickened or discolored during healing, obtain mycological confirmation (KOH preparation and fungal culture) before starting antifungal therapy, as approximately 50% of dystrophic nails are non-fungal 8
- Do not ignore signs of infection: Green discoloration indicates Pseudomonas and requires topical povidone-iodine treatment 7, 8