Subungual Exostosis and Hematoma

Ovid: 5-Minute Sports Medicine Consult, The

Subungual Exostosis and Hematoma
Kathleen Weber
  • Subungual exostosis: Solitary, benign, bony growth from the distal phalanx's terminal tuft commonly causing deformity of the nail (1)
  • Subungual hematoma: Acute, traumatic, subungual collection of blood, manifested by an area of black or blue discoloration, usually caused by a direct blunt impact or chronic, repetitive stresses to the nail unit (2)
  • Synonym(s) for subungual hematoma: Tennis toe; Jogger's toe; Sportsman's toe
Subungual exostosis:
  • Relatively uncommon (1,3)
  • Seen more commonly after the 2nd and 3rd decades of life (1)
  • Usually affects the great toe, but can occur on the lesser toes or, rarely, a finger (1)
Risk Factors
  • The cause of subungual exostosis is unknown (3).
  • Suggested causal factors include trauma (3), tumor, chronic infection, or hereditary abnormality.
General Prevention
Subungual hematoma:
  • Well-fitted footwear with a snug midfoot and a wide toe box
  • Keep nails trimmed.
  • Orthotic devices
  • Repeated contact of the toes with the front of the shoebox causes toenail dyshesion and subsequent hemorrhage (4).
  • If the activity continues, it may lead to chronic nail dystrophy, nail loss, and callus formation of the tip of the toe (4).
  • Subungual hematomas are seen more commonly in sports that require frequent pivoting, abrupt stops, or repetitive kicking (eg, basketball, handball, racquet sports, soccer, football, running).
  • Trauma (eg, fingertip slammed in a car door, hammer blow, or blunt trauma)
Subungual exostosis:
  • Pain and swelling over the exostosis can affect gait.
  • Pain associated with trauma is common because the tumor protrudes and is easily traumatized.
  • Inquire whether the pigment was present at birth or acquired.
  • Specific questions pertaining to athletic activities, recent trauma, and physical exertion
  • Obtaining a thorough medication history of any medications may help identify drugs that may contribute to abnormal nail pigmentation.
Physical Exam
  • Subungual exostosis:
    • Gait may be affected secondary to pain and swelling related to the subungual bony growth.
    • Direct trauma to a protruding exostosis may elicit significant pain.
  • Subungual hematoma:
    • Collection of blood, reddish to reddish-black pigmentation, under the nail with or without edema/erythema
    • Can be extremely painful with throbbing pain
    • Hematoma may be painless with minor trauma.
  • Subungual exostosis:
    • Presence of a firm mass noted at the distal portion of the terminal phalanx
    • Nail plate can be elevated laterally by the tumor, but is rarely injured.
    • Pain elicited with direct pressure
  • Subungual hematoma:
    • Examine nail unit and the periungual skin (5).
    • May note a callus on the skin distal to the affected nail.
    • Observe for any extension of discoloration from under the nail plate into the proximal nailfold and nail matrix (Hutchinson melanotic whitlow sign); suspect subungual melanoma.
    • The pigment in a subungual hematoma is homogenous in distribution, while melanocytic lesions have cellular inclusions (5).
    • Toes most likely affected in sport-specific pattern are:
      • “Tennis toe”: More commonly lateral nail of the hallux or 2nd toe, depending on which is longer
      • “Jogger's toe”: 2nd through 5th toes
      • Kicking sports: 2nd or 3rd toe
Diagnostic Tests & Interpretation
  • Subungual exostosis:
    • Radiograph mandatory if hard subungual mass noted on examination
    • A subungual exostosis and an enchondroma may involve the distal portion of a phalanx with associated nail changes.
    • Radiographs differentiate an exostosis from an enchondroma.
    • Radiographically, an exostosis is a bony outgrowth projecting from the distal phalanx's tuft, while a radiolucent enchondroma results in expansion of the phalanx itself.
  • Subungual hematoma:
    • Anteroposterior, lateral, and oblique radiographs should be obtained when a hematoma involves >25% of the visible nail to assess for fracture.
    • Obtain radiographs when a fracture is suspected.
Diagnostic Procedures/Surgery
A chronic nontraumatic lesion may require a biopsy of the underlying nail matrix and/or nail bed to rule out a pigmented lesion.
Differential Diagnosis
  • Subungual exostosis (1):
    • Subungual osteochondroma: Histologically, the exostosis has a fibrous cartilage cap over the bony growth and the osteochondroma has hyaline cartilage (6).
    • Fibroma
    • Subungual verruca vulgaris
    • Glomus tumor
    • Enchondroma
    • Multiple exostosis: Consider an autosomal-dominant multiple exostosis syndrome.
  • Subungual hematoma (5):
    • Subungual benign and malignant tumors (eg, melanoma)
    • Onychomycosis
    • Glomus tumor (extremely painful nodule under the nail; pain worse when exposed to cold temperatures)
    • Subungual exostosis


Ongoing Care
Follow-Up Recommendations
Further evaluation with radiographs (exclude exostosis) and possibly a biopsy are required when a suspected subungual hematoma does not grow out distally as the nail plate grows, or if there is recurrence of the hematoma (5).
Patient Education
Subungual hematoma:
  • To prevent infection following a trephination of the hematoma, instruct the patient on proper wound care, including:
    • Observing and reporting any signs of infection
    • Keeping the area clean and dry
    • Avoidance of swimming, hot tub, and whirlpool use
  • Inform the patient that they will eventually lose the affected nail and a new nail will grow out, typically within 2–6 mos.
  • Wear well-fitted footwear with a snug midfoot and a wide toe box.
  • Keep nails trimmed.
  • Orthotic devices if appropriate
Prognosis for both a subungual exostosis and a hematoma is excellent.
  • 726.91 Exostosis of unspecified site
  • 923.3 Contusion of finger
  • 924.3 Contusion of toe

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More