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Subungual Hematoma

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Other Names

  • Nail blister
  • Fingernail blister
  • Toenail blister
  • Acute Traumatic Subungual Hematoma


  • This page refers to a painful hematoma underneath the fingernail or toenail


  • General
    • Definition: blood that is trapped under the nail after trauma
    • Can occur in either fingers or toes
    • Occurs after either acute trauma, typically a crush injury
  • Types
    • Simple: the nail and nail fold are intact
    • Complex: accompanied by significant injuries to the nail fold and digit


  • Trauma, examples include
    • Crush in car door
    • Stubbing one's toe
  • Subsequently, there is bleeding under the nail
    • Leads to formation of subungual hematoma

Associated Conditions


Risk Factors

  • Unknown

Differential Diagnosis

Clinical Features

  • History
    • Patients will describe some form of trauma
    • Throbbing pain of the digit
    • Often red, black or blue discoloration under the nail
  • Physical Exam Physical Examination Hand
    • Evaluate for nailbed injuries, deformities, loss of flexion or extension
    • Typically will have dark or purple discoloration under the nail of the affected digit
    • Patient may be tender in the same distribution




  • N/A



  • Indications
    • Vast majority of cases
    • Intact or minimal disruption to nail fold, nail and phalanx
    • Most cases can be managed by emergency medicine or primary care physicians
    • Indications for referral to sub specialist
      • Displaced fractures
      • Intraarticular fractures
      • Extensive nail bed injury
      • Infected wounds
  • No treatment
    • Can strongly be considered if patient or athlete has no symptoms
  • Analgesics
  • Nail Trephination (decompression)
    • Indications: if <50% of nail involved, < 24-48 hours old, symptomatic
    • Contraindications: patients with obvious deformity, nail avulsion, >48 hours old
    • Use electro-cautery or 18-gauge needle
    • For most patients, this provides immediate relief of pain
  • Nail Removal, drainage and nail bed repair
    • Indications: associated nailbed avulsion, complex laceration, fingertip or toe avulsion
    • Not routinely indicated if nail, nail fold intact
    • Can be considered if >50% of nail is involved, although this is controversial
    • Not required if fracture is present (controversial?)
    • Requires Digital Block
  • Consider antibiotics in
    • Patients with tuft fracture
    • High risk patients (diabetes, immunocompromised, etc) with any open fracture
    • Salter-Harris fracture (Seymour fracture)
  • Tetanus Prophylaxis as indicated
  • In the setting of repetitive microtrauma, proper footwear can help decrease recurrence


  • Indications
    • Not routinely necessary unless co-occurring injury (i.e. fracture, nailbed laceration)
  • Procedure
    • Nailbed removal and exploration
    • Laceration repair

Rehab and Return to Play


  • Generally, no rehabilitation is required

Return to Play/ Work

  • Players can typically return to play immediately

Complications and Prognosis


  • Overall outcomes
    • About 2/3 of patients report excellent or very good outcomes after trephination[2]
  • Financial implications
    • Significantly higher costs associated with nail removal and nail bed exploration[3]
  • Size of hematoma
    • Historically, hematoma >50% would indicate nailbed removal and repair, however several recent studies have failed to show a difference in short- or long-term outcomes, including the presence of infection or nail deformity with removal vs trephination[4][5]
  • Complications
    • More likely to occur if there is a delay in care[6]


  • Poor nailbed cosmesis
    • Including deformity, loss
  • Onycholysis (separation of the nail plate from the nail bed)
  • Infection
    • No apparent correlation between size of hematoma and risk of infection (need citation)

See Also



  1. Simon RR, Wolgin M. Subungual hematoma: association with occult laceration requiring repair. Am J Emerg Med. 1987 Jul;5(4):302-4.
  2. Meek S, White M. Subungual haematomas: is simple trephining enough? J Accid Emerg Med. 1998 Jul;15(4):269-71.
  3. Roser SE, Gellman H, Comparison of nail bed repair versus nail trephination for subungual hematomas in children, J Hand Surg 24(6):1166�1170, 1999.
  4. Roser SE, Gellman H. Comparison of nail bed repair versus nail trephination for subungual hematomas in children. J Hand Surg Am. 1999 Nov;24(6):1166-70.
  5. Seaberg DC, Angelos WJ, Paris PM. Treatment of subungual hematomas with nail trephination: a prospective study. Am J Emerg Med. 1991 May;9(3):209-10.
  6. Chung S. Minor lesions. In: Textbook of Pediatric Emergency Medicine, 7th edition, Shaw KN, Bachur RG (Eds), Wolters Kluwer, Philadelphia 2016. p.1362.
Created by:
John Kiel on 1 September 2019 22:04:37
Last edited:
16 October 2022 00:23:07
Lower Extremity | Trauma | Finger | Foot | Upper Extremity | Acute