The Half Moon Nail

aka Bone and Joint Bamboozler 006

40 year old male attends with acutely painful toe following a weekend DIY incident.

[Sledgehammer 1 – Man 0]

Subungual haematoma great toe

What is the diagnosis?

Bamboozler Answer

Subungual Haematoma

  • Subungual haematomas occur when there is bleeding beneath the nail. Generally caused traumatically by getting it caught between to hard surfaces.
  • The haematoma becomes trapped between the rigid structures of the nail above and the distal phalanx below.
  • The space occupying mass causes intense pain secondary to increased pressure against the very sensitive nail bed and matrix.

How would you assess this injury?

Bamboozler Answer

Examination should include:

  • Testing extensor and flexor tendons
  • Testing circulation by capillary refill
  • Checking the sensitivity to the area


  • X-rays are generally indicated to rule out crush injury or fracture to the distal phalanx
  • Document the percentage of nail bed covered by the haematoma, surrounding damage to tissues, nail-bed, and nail margins.

What are the potential complications?

Bamboozler Answer
  • Fracture to the distal phalanx
  • Crush injury
  • Nail bed injury
  • Performing trephination on subungual ecchymosis.

If no history of trauma or story doesn’t fit with subungual haematoma consider melanoma, Kaposi’s sarcoma, and other tumors.

What are the treatment options?

Bamboozler Answer

Wait and See:

Patients who are not experiencing significant pain at rest, should not have trephination performed, and can be treated with simple analgesia, rest, ice, and a protective splint.


Trephination gives good cosmetic and functional result in both adults and children as long as no other fingertip injury is present.

Trephination makes a closed wound open, and introduces the risk of bacteria entering causing infection, once procedure completed and haematoma evacuated no need to further soak digit, and a protective dressing should be applied for 7-10 to prevent infection.

LITFL: Subungual haematoma trephination. Procedure




Bone and Joint Bamboozler

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC


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