Subungual hematoma

Background

• Collection of blood under the nail
• There is a strong association with distal phalanx fractures.
• In the past, complete nail removal and exploration and closure of possible nail bed lacerations was performed. A prospective study of 52 children supports management with trephination alone for any size hematoma.
• Atraumatic subungual hematoma may be caused by melanoma or Kaposi's sarcoma

Types

1. Simple: No nailbed dislocation or evidence of open fracture
2. Complex: Aassociated with fracture or nail plate disruption

Nailtip Anatomy

A. Nail plate; B. lunula; C. root; D. sinus; E. matrix; F. nail bed; G. hyponychium; H. free margin.

• The perionychium includes the nail bed and the paronychium.
• The paronychium is the lateral nail fold (soft tissue lateral to the nail bed).
• The hyponychium is the palmar surface skin distal to the nail.
• The lunula is that white semi-moon shaped proximal portion of the nail.
• The sterile matrix is deep to the nail, adheres to it and is distal to the lunule.
• The germinal portion is proximal to the matrix and is responsible for nail growth.

Clinical Features

Subungal hematoma

• Blood trapped under nail

Differential Diagnosis

Distal Finger (Including Nail) Injury

• Distal interphalangeal dislocation (finger)
• Distal phalanx (finger) fracture
• Finger amputation
• Fingertip avulsion
• Finger infection
• Nailbed laceration
• Nail avulsion
• Subungual hematoma

Hand and finger injuries

• Distal finger
  • Finger amputation
  • Fingertip laceration
  • Nail avulsion
  • Nailbed laceration
  • Subungual hematoma
• Other finger/thumb
  • Boutonniere deformity
  • Mallet finger
    • Swan neck deformity
  • Jammed finger
  • Jersey finger
  • Trigger finger
  • Ring avulsion injury
  • De Quervain tenosynovitis
  • Infiltrative tenosynovitis
  • Metacarpophalangeal ulnar ligament rupture (Gamekeeper's thumb)
• Hand
  • Dupuytren contracture
• Wrist
  • Drummer's wrist
  • Ganglion cyst
  • Lunotriquetral ligament instability
  • Scaphoid fracture
  • Extensor digitorum tenosynovitis
  • Compressive neuropathy ("bracelet syndrome")
  • Intersection syndrome
  • Snapping Extensor Carpi Ulnaris
  • Vaughn Jackson syndrome
• General
  • Hand and finger dislocations
  • Hand and finger fractures
  • Hand and finger infections
  • Gout and pseudogout
  • Hand and finger tendon injuries
  • High-pressure injection injury
  • Osteoarthritis
  • Rheumatoid arthritis
  • Ring removal

Evaluation

• Clinical diagnosis
• Evaluate percentage of nail bed involved, test extensor/flexor tendons and distal cap refill

Management

Simple

All blood has been expelled through the trephination hole

• Trephination
  1. Cleanse with povidone-iodine solution (not flammable alcohol)
  2. Handheld cautery works best - no anesthesia is required
  3. Alternatively a needle spun in a drilling fashion
  4. Sharp object (i.e. safety pin) heated with flame in an austere environment
• Indicated for acute sublingual hematomas (less than 24 to 48 hours old)
• If a fracture is present, the digit should be splinted
• Instruct patients to soak affected finger in warm water BID-TID x7d
• Prophylactic antibiotics are not needed after trephination of uncomplicated hematomas

Complex

• Nail removal only recommended if there is associated nail avulsion or nail fold disruption
• Repair nailbed laceration using absorbable sutures

Contraindications

• Electrocautery
  • Presence of acrylic nails secondry to fire risk. Remove acrylic nails before using electrocautery tool.

Disposition

• Discharge

See Also

• Hand and finger diagnoses
• Nailbed laceration