summary Felons are subcutaneous abscesses of the fingertip pulp. Diagnosis is made clinically by assessing for tenderness, erythema and fluctuance of the fingertip pulp. Treatment is usually I&D and IV antibiotics. Epidemiology Incidence accounts for 15-20% of hand infections Anatomic location most commonly occurs in the thumb or index finger Etiology Pathophysiology mechanism of injury penetrating injury login to view 2 more bullets local spread login to view 1 more bullet no history of injury in 50% of patients login to view 1 more bullet pathophysiology overview login to view 1 more bullet progression login to view 4 more bullets organisms Staphylococcus aureus login to view 1 more bullet gram negative organisms login to view 1 more bullet Eikenella corrodens login to view 1 more bullet Anatomy Fingertip pulp closed sac connective tissue framework separated by fibrous vertical septae running from periosteum of the distal phalanx to the epidermis provides structural support stabilizes the pulp during pinch and grasp contains eccrine sweat glands that open onto the epidermis Blood supply digital arteries run parallel to the distal phalanx gives off a nutrient branch to the epiphysis before entering the pulp space Presentation Symptoms severe throbbing pain Physical exam swelling does not extend proximal to DIP flexion crease unless flexor tendon sheath or joint is involved tenderness Imaging Radiographs indications only indicated if history of trauma to rule out fracture or foreign body MRI indications not indicated Studies Serum Labs not indicated Differential Herpetic Whitlow Paronychia Glomus Tumor Mucous cyst Psoriasis Diagnosis Clinical diagnosis is made with careful history and physical examination Treatment Nonoperative oral antibiotics and observation indications login to view 1 more bullet Operative bedside I&D and IV antibiotics indications login to view 1 more bullet Techniques Bedside I&D anesthesia digital block approach keep incision distal to DIP crease login to view 1 more bullet mid-lateral approach login to view 2 more bullets volar longitudinal approach login to view 2 more bullets incisions to avoid login to view 4 more bullets debridement avoid violating flexor sheath or DIP joint to prevent spread into these spaces break up septa to decompress infection and prevent compartment syndrome of fingertip obtain gram stain and culture login to view 1 more bullet place gauze wick postoperative routine dressing changes Complications Finger tip compartment syndrome Flexor tenosynovitis Osteomyelitis Digital tip necrosis Prognosis If left untreated, can lead to sequestration of the diaphysis of the distal phalanx pyogenic arthritis of the DIP joint flexor tenosynovitis from proximal extension