Pediatric Submandibular Lymphadenitis Caused by Mycobacterium houstonense: A Case Report and Literature Review

Infection caused by Mycobacterium houstonense is rare. A literature review suggested that M. houstonense infections mainly affect adults with open fractures or wounds. Here, we report a pediatric case of submandibular lymphadenitis caused by M. houstonense. The strain was identified using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing. The patient was successfully treated with a six-month combination regimen of linezolid, clarithromycin, amikacin, and cefoxitin, with the modification that trimethoprim-sulfamethoxazole was used instead of cefoxitin for the final four months. The pediatric patient was monitored monthly with complete blood counts and liver function tests throughout the treatment course. No adverse events were observed, and clinical cure was achieved.