Subungual Exostosis and Hematoma

By admin On Nov 8, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Kathleen Weber

Basics

Description

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

Epidemiology

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

Etiology

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)

Diagnosis

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.

History

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

Imaging

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

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Treatment

Subungual exostosis:
- Excision of tumor (1)[C]
Subungual hematoma:
- Immediate elevation and application of ice or immersion in ice water may reduce pain and bleeding.
- An acute subungual hematoma can be evacuated by puncturing the nail plate overlying the hematoma using thermal cautery, laser, or a drill (ie, 18-gauge needle, scalpel blade, dental bur) (2,4,7)[C].
- Evacuation is performed by directing the preferred heated trephine perpendicular to the nail plate overlying the hematoma; slow and gentle pressure is applied until blood is expressed from the nail plate.
- Nail removal if the normal architecture of the nail plate or its surrounding structures has been damaged (2,7)[C]
- Wound repair if needed (7)[C]

Additional Treatment

Referral

Chronic lesions should be referred for evaluation for the possibility of a subungual melanoma.

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

Prognosis for both a subungual exostosis and a hematoma is excellent.

Complications

Infection, although an uncommon complication, following an excision of a subungual exostosis or an evacuation of the hematoma of a subungual hematoma may occur.
Recurring subungual hematomas of the same nail bed secondary to repetitive trauma may predispose the nail bed to onychomycosis.

References

1. Guarneri C, Guarneri F, Risitano G, et al. Solitary asymptomatic nodule of the great toe. Int J Dermatol. 2005;44:245–247.

2. Salter SA, Ciocon DH, Gowrishankar TR, et al. Controlled nail trephination for subungual hematoma. Am J Emerg Med. 2006;24:875–877.

3. Campanelli A, Borradori L. Images in clinical medicine. Subungual exostosis. N Engl J Med. 2008;359:e31.

4. Cordoro KM, Ganz JE. Training room management of medical conditions: sports dermatology. Clin Sports Med. 2005;24:565–598, viii–ix.

5. Braun RP, Baran R, Le Gal FA, et al. Diagnosis and management of nail pigmentations. J Am Acad Dermatol. 2007.

6. Lee SK, Jung MS, Lee YH, et al. Two distinctive subungual pathologies: subungual exostosis and subungual osteochondroma. Foot Ankle Int. 2007;28:595–601.

7. Batrick N, Hashemi K, Freij R. Treatment of uncomplicated subungual haematoma. Emerg Med J. 2003;20:65.

Codes

ICD9

726.91 Exostosis of unspecified site
923.3 Contusion of finger
924.3 Contusion of toe