Primary atrophic rhinitis associated with Klebsiella pneumoniae subsp. ozaenae: a case report with microbiological correlation

Abstract

Primary atrophic rhinitis (ozena) is a chronic, debilitating nasal disorder characterized by progressive mucosal atrophy, crust formation, foul smell, and widening of the nasal cavity. Although its etiology is multifactorial, K. pneumoniae subsp. ozaenae has been frequently associated with this condition, although its exact pathogenic role remains debated. Early microbiological diagnosis and confirmation is essential for targeted antimicrobial therapy and prevention of chronic complications. A 32-year-old male presented with chronic nasal crusting, foul-smelling discharge, and recurrent upper respiratory tract infections. Computed tomography (CT) of the paranasal sinuses revealed pansinusitis with bilateral osteomeatal complex obstruction. Direct microscopy showed no acid-fast bacilli or fungal elements. Culture of nasal crust specimens yielded mucoid, non-lactose fermenting colonies identified as K. pneumoniae subsp. ozaenae using conventional biochemical tests and also confirmed by automated VITEK 2 (bioMérieux). Antimicrobial susceptibility testing (Kirby-Bauer method, CLSI guidelines) demonstrated susceptibility to amoxicillin-clavulanate, piperacillin-tazobactam, cefepime, aminoglycosides, ciprofloxacin, cotrimoxazole, and carbapenems, with resistance to ceftriaxone. The patient improved following culture-directed oral ciprofloxacin therapy combined with local nasal care. This case highlights the diagnostic challenge in distinguishing colonization from pathogenic involvement and emphasizes the importance of clinicomicrobiological correlation. Culture-guided therapy ensures favourable outcomes and supports antimicrobial stewardship.