- Wound culture: Staphylococcus Aureus 3+; Serratia Liquefaciens 2+ (Gram negative rod)
- Radiograph: There is soft tissue swelling with likely ulcer formation involving the distal volar tip of the third phalanx. There is associated bony erosion involving the third distal phalanx worrisome for associated acute osteomyelitis
A felon usually is caused by inoculation of bacteria into the fingertip through a penetrating trauma. The most commonly affected digits are the thumb and index finger. Common predisposing causes include splinter, bits of glass, abrasions, and minor puncture wounds. A felon also may arise when an untreated paronychia spreads into the pad of the fingertip. Felons have been reported following multiple finger-stick blood tests.