A Case of Axillary Lymphadenitis Caused by Methicillin-Resistant Staphylococcus aureus

Abstract

We report the case of an 11-year-old male patient with right axillary lymphadenitis caused by methicillin-resistant Staphylococcus aureus (MRSA) associated with bullous impetigo. Bumps on the flexor surface of his right elbow appeared approximately two weeks before admission. The bumps spread to the right armpit and left elbow through scratching, and they scabbed over. The patient visited a local clinic three days before admission because of right axillary pain and fever, where he was diagnosed with lymphadenitis. His symptoms did not improve despite antibiotic treatment. Upon admission to our hospital, he was unable to fully elevate his right arm due to pain. His axilla was swollen and a 5 cm abscess with swollen lymph nodes was detected by ultrasound and enhanced computed tomography scan. Under general anesthesia, an incision and drainage procedure were performed, and his symptoms improved. He became afebrile and was able to elevate his right arm two days after drainage. MRSA was identified in the pus from the abscess as well as on the impetigo surface of his arm. His lymphadenitis appeared to be caused by MRSA through the impetigo scar. Incision and drainage proved to be effective for the treatment of lymphadenitis with an abscess following a prolonged duration of symptoms. Furthermore, MRSA should be considered as the cause when the lymphadenitis is resistant to antibiotic treatment.