Atypical Mycobacterium Detection in Refractory Chronic Rhinosinusitis

Abstract

Atypical mycobacterium (AM) involvement in refractory chronic rhinosinusitis (CRS) is sought by some surgeons with customary acid-fast bacilli cultures (AFBC) in the operating room (OR). We evaluate our experience with AM in CRS by describing (1) associated risk factors, (2) species identified, and (3) frequency of positive cultures in clinic versus OR. Case series with chart review. Tertiary rhinology practice. AFBC taken between 2005 and 2011 were identified from a microbiology laboratory database. Charts were reviewed for gender, age, medical history, risk factors for AM, pathogen types, and treatments, with statistical comparison using Pearson χ(2). The benefit of "targeted AFBC" for cases with high clinical suspicion was compared with "customary AFBC" in the OR. Thirty-seven patients were identified with AM, of which 10 had one or more risk factors for AM including foreign body (n = 4), non-HIV immune dysfunction (n = 4), and previous chemoradiation (n = 4). Six different AM species were identified: most frequently Mycobacterium abscessus (57.1%), followed by Mycobacterium avium-intracellulare complex (14.3%) and Mycobacterium chelonae (14.3%). "Targeted AFBC" from the outpatient setting were positive in 10 of 190 (5.3%) patients, whereas 10 of 373 (2.6%) patients of "customary AFBC" in the OR were positive (P = .12). Macrolide therapy was employed in 23 of 37 (62%) patients with AM-associated CRS but was not prescribed in patients with positive "customary AFBC" alone. AM-associated CRS is an uncommon condition that can occur in the absence of foreign body or overtly altered innate/adaptive immunity. Indications and efficacy of macrolide therapy, as well as the potential relationships between existence of AM in tap water, AM biofilms, and frequent use of nasal irrigations warrant further investigation in refractory CRS.