31911 Postsurgical atypical mycobacterial infection misdiagnosed as pyoderma gangrenosum

Abstract

Background: Infection must be excluded in the evaluation of pyoderma gangrenosum (PG), and is frequently identified in misdiagnosed cases of PG that are “recalcitrant” to treatment. Biopsy and tissue culture should be taken with special attention given to the prolonged time it may take for atypical mycobacteria to be identified and speciated. Observation: A 50-year-old woman presented with a 7-month history of unilateral erythema, induration, and purulent drainage following breast reduction surgery. She had been treated for presumed PG with a brief course of antibiotics and daily oral prednisone over 4 months. Attempts to wean prednisone below 10 mg daily resulted in worsening disease. Tissue culture revealed mycobacterium growth and the patient was started on minocycline. Mycobacterium abscessus, resistant to minocycline, was subsequently speciated. The patient was referred to infectious disease, who initiated a four-month course of antibiotic therapy with amikacin and omadacycline. Comments: M abscessus represents one of the commonly identified nontuberculous mycobacteria (NTM) species causing severe respiratory, skin, and mucosal disease. Its rising prevalence is complicated by its significant antibiotic resistance. Outbreaks of postsurgical atypical mycobacterial infections have been reported following video-assisted surgical procedures and surgeries requiring the use of nonautoclavable instruments that may be contaminated by M abscessus biofilm. Concern for PG involving a surgical site should raise suspicion for NTM infection, and cultures should be performed.