A 28 year old male presents for finger pain. He works in construction and accidentally poked his right index finger with a stray nail a few days ago. Since then, the palmar aspect of his fingertip has become progressively more swollen and painful. Vital signs are within normal limits. On exam, the right upper extremity is neurovascularly intact with full range of motion. There is erythema, fluctuance, and severe pain to palpation over the distal pulp of his second digit. There is no pain to palpation proximally along the finger. What organism is the most common cause of this patient’s diagnosis?
A: Methicillin-resistant S. aureus (MRSA)
B: Methicillin-sensitive S. aureus (MSSA)
C: Pseudomonas aeruginosa
D: Streptococcus pyogenes
Answer: Methicillin-resistant S. aureus (MRSA)
This patient is presenting with a felon, a subcutaneous pyogenic infection of the distal finger or thumb. The infection typically results from a minor puncture wound which later becomes an abscess confined to the small compartments of the finger pad. Treatment commonly involves incision and drainage in addition to oral antibiotics. Thus, it is extremely important that the antibiotics appropriately cover MRSA as improperly treated felons may worsen to cause flexor tenosynovitis or osteomyelitis. MSSA and Streptococcus pyogenes are other common causes of felons but not as common as MRSA. Pseudomonas is not a common cause of felons.
References:
Wilson PC, Rinker B: The incidence of methicillin-resistant Staphylococcus aureus in community-acquired hand infections. Ann Plast Surg 62: 513, 2009. [PubMed: 19387151]
Germann CA. Nontraumatic Disorders of the Hand. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill Education; 2020.
