Intractable Otitis Media Presenting as Falsely Positive for Proteinase 3-ANCA: A Case Report

J Int Adv Otol. 2018 Aug;14(2):337-340. doi: 10.5152/iao.2018.4746.

Abstract

Herein, we report a case of otitis media caused by methicillin-resistant Staphylococcus aureus (MRSA), presenting as falsely positive for proteinase 3 (PR3)-antineutrophil cytoplasmic antibodies (ANCA). A 47-year-old woman was referred to our hospital with a complaint of left otorrhea. An otorrhea culture yielded MRSA, and the patient was treated using tympanoplasty. Postoperative administration of teicoplanin lead to drug-induced neutropenia and was discontinued 4 days after the operation. One month after the operation, the patient's otorrhea recurred, and it was accompanied by hearing impairment. The otorrhea culture yielded MRSA again, while serum was positive for PR3-ANCA (6.8 U/mL). As MRSA was detected in the patient's otorrhea sample, she was treated with linezolid. Her symptoms then improved immediately. Although the PR3-ANCA positivity remained, the patient's otorrhea and hearing impairment had not recurred for 3 years when this report was submitted. Therefore, we conclude that this is a case of false PR3-ANCA positivity.

Publication types

  • Case Reports

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Antibodies, Antineutrophil Cytoplasmic / metabolism*
  • False Positive Reactions
  • Female
  • Hearing Loss / diagnosis
  • Hearing Loss / etiology
  • Humans
  • Linezolid / administration & dosage
  • Linezolid / therapeutic use
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification*
  • Middle Aged
  • Myeloblastin / metabolism*
  • Otitis Media / diagnosis*
  • Otitis Media / metabolism
  • Otitis Media / microbiology
  • Otitis Media / surgery*
  • Recurrence
  • Treatment Outcome
  • Tympanoplasty / methods

Substances

  • Anti-Bacterial Agents
  • Antibodies, Antineutrophil Cytoplasmic
  • Myeloblastin
  • Linezolid