What are the differential diagnoses for a 25-year-old with a great toe injury, loosened nail, and slight bleeding after catching the nail on carpet?

Differential Diagnoses for Traumatic Great Toe Nail Injury

This is a traumatic nail injury with a broken nail plate and minimal bleeding, not an infection or systemic disease process requiring extensive workup. The primary differentials focus on the extent of nail apparatus damage and potential complications from the initial trauma.

Primary Differential Diagnoses

Nail Plate Fracture with Nail Bed Laceration

• Most likely diagnosis given the mechanism of catching the loosened nail on carpet and bending it back with central breakage and slight bleeding 1
• The bleeding indicates disruption of the underlying nail bed, which is highly vascular 2
• Nail bed lacerations commonly occur with nail plate avulsion or fracture, particularly when force is applied to a previously loosened nail 1

Simple Nail Plate Avulsion (Partial)

• The nail was already loosened from the initial stubbing injury 3 months ago, and the recent trauma caused partial separation with breakage 3
• Partial avulsion can occur without significant nail bed injury if the nail plate breaks cleanly 1
• The "slight bleeding" suggests minimal underlying tissue disruption

Subungual Hematoma (Resolving or New)

• May have had a subungual hematoma from the original injury 3 months ago that contributed to nail loosening 4, 5
• The recent trauma could have caused a new small hematoma, though the description of "slight bleeding but not currently bleeding" suggests external rather than subungual blood 3
• Subungual hematomas typically present with visible blood collection under the nail plate and significant pain from pressure 4

Distal Phalanx Fracture (Less Likely but Important to Exclude)

• There is a high incidence of associated distal phalangeal fracture with significant nail trauma 2
• The initial stubbing injury 3 months ago could have caused an undiagnosed fracture 6
• However, the patient has been ambulatory for 3 months, making acute fracture from the original injury less likely unless there was malunion or nonunion

Secondary Considerations (Lower Priority)

Nail Matrix Injury

• The original trauma may have damaged the nail matrix, leading to abnormal nail growth and the loosening observed 2
• Matrix injury can result in permanent nail deformity if not properly managed 2

Superficial Soft Tissue Laceration

• The broken nail may have caused a small laceration to the surrounding skin or hyponychium 1
• This would explain the slight bleeding that has now stopped

Critical Exclusions in This Case

This is NOT a diabetic foot infection scenario - The patient is 25 years old with clear traumatic etiology and no mention of diabetes, neuropathy, or systemic symptoms 7. The extensive diabetic foot infection guidelines provided 7 are not applicable to this clinical scenario.

No signs of infection are present - There is no mention of erythema, warmth, purulent discharge, or systemic symptoms that would suggest infection 7. The slight bleeding was from the acute trauma, not from infected tissue.

Recommended Immediate Assessment

• Examine for active bleeding - Ensure hemostasis has been achieved 1
• Assess nail bed integrity - Look for visible lacerations or exposed nail bed tissue 1
• Evaluate for subungual hematoma - Check for blood collection under remaining nail plate 4, 5
• Palpate distal phalanx - Assess for point tenderness suggesting fracture 2
• Check neurovascular status - Ensure intact sensation and capillary refill distally 1

Imaging Consideration

• Plain radiographs are indicated if there is significant tenderness over the distal phalanx, given the high association between nail trauma and phalangeal fractures 2
• Radiographs should be obtained even with seemingly minor trauma if clinical suspicion exists 6