Subungual hematoma


  • 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.[1]
  • Atraumatic subungual hematoma may be caused by melanoma or Kaposi's sarcoma


  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 perinychium includes the nail, the nailbed, and the surrounding tissue.
  • The paronychia is the lateral nail folds
  • 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

Hand and finger injuries


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



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 [2]



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


  • Discharge

See Also


  1. Roser SE, Gellman H. Comparison of nail bed repair versus nail trephination for subungual hematomas in children. J Hand Surg. 1999;24(6):2266-1170.
  2. Holtzman L. Incision and Drainage. In: Roberts and Hedges' Clinical Procedures in Emergency Medicine. 6th ed. Philadelphia, PA: Elsevier; 2014.
  3. Seaberg DC, ANgelos WJ, et al. Treatment of subungual hematomas with nail trephination: a prospective study. Am J Emerg Med. 1991; 9(3):209-210