Subungual Hematoma

Introduction

Subungual hematoma refers to blood that is trapped under the nail after trauma (e.g. crush in a door jamb, stubbing one's toe, tight or ill-fitting shoes).

• Patients often complain of throbbing pain (due to build-up of pressure under the nail) and blue-black discolouration under the nail as the hematoma progresses.

NOTE: Rarely, subungual hematoma is associated with a malignant tumour of the nail unit, such as squamous cell carcinoma or melanoma.

Management

In the majority of cases, small hematomas with minimal pain require no treatment.

• Pain medication or practice RICE method, if needed.
• The trapped blood will eventually be reabsorbed, and the dark mark will disappear. This can take 2-3 months for a fingernail and up to 9 months for a toenail.

However, if subungual hematoma is acute painful (<48 hours after the injury), trephination (drain the hematoma by creating a hole in the nail) can be considered.

• Pain is relieved immediately for most patients with simple nail trephination.

Occasionally, the nail plate is best removed and the nailbed surgically repaired.

NOTE: A plain X-ray should be considered for extensive nailbed injuries or large subungual hematomas that occupy >50% of the nail plate to assess for an underlying fracture.

External Links

• Medical News Today - Subungual hematoma: Images, treatment, and link to melanoma
  
• DermNet - Subungual Haemorrhage