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Malignant Otitis Externa: Evolving Pathogens and Implications for Diagnosis and Treatment.
Candace E Hobson1, Jennifer D Moy1, Karin E Byers2
1Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
Summary
Malignant otitis externa (MOE) can be caused by organisms other than Pseudomonas aeruginosa, including methicillin-resistant Staphylococcus aureus (MRSA). Non-Pseudomonas infections may present differently, particularly in patients without diabetes.
Area of Science:
- Infectious Diseases
- Otolaryngology
- Bacterial Infections
Background:
- Malignant otitis externa (MOE) is a severe invasive infection of the temporal bone.
- Pseudomonas aeruginosa is the classic causative agent, but non-pseudomonal infections are increasingly recognized.
Purpose of the Study:
- To compare the clinical presentation and outcomes of MOE caused by Pseudomonas versus non-Pseudomonas organisms.
- To evaluate the role of methicillin-resistant Staphylococcus aureus (MRSA) in MOE.
Main Methods:
- Retrospective case series with chart review of adult patients diagnosed with MOE between 1995 and 2012.
- Analysis of clinical presentation, laboratory data, treatment, and outcomes for Pseudomonas and non-Pseudomonas infections.
Main Results:
- Nine of twenty MOE patients (45%) had Pseudomonas infections; three (15%) had MRSA infections.
- Clinical presentation was similar, but Pseudomonas infections were more common in diabetic patients.
- Non-Pseudomonas infections, including MRSA, required longer antibiotic treatment durations.
Conclusions:
- Maintain a high suspicion for non-Pseudomonas organisms in MOE, especially in non-diabetic patients.
- MRSA is an emerging pathogen in malignant otitis externa.
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