A 70-year-old female presented with two days of sudden pain and swelling involving the lateral distal nail fold of one finger. She is otherwise healthy with no history of trauma or exposure.
This was a lateral nail fold paronychia presumed to be due to Staphyloccal aureus. It responded to a 1-week course of cephalexin.
Differential Diagnosis: Felon affects the distal fingertip pulp and whitlow is a herpes simplex infection of the digit. Infectious flexor tenosynovitis affects the palmar aspect of the finger and an ingrown fingernail is a foreign body reaction that can sometimes become secondarily infected.