Allergy and Bacterial Infection in a Suburban Otolaryngology Clinic
Akshay Mehta BA, MS, and Michael Morris, MD

Objective
Upper respiratory tract infection and allergy remain the most common and challenging aspects of outpatient medicine. Both allergic and infectious disease either alone or in combination contributes to difficulty in deciding upon treatment algorithms. The influence of allergy on pathogen selectivity in nasal cultures was studied in an effort to further refine treatment selection.

Method
Over a 6 month period, 130 patients presenting for otolaryngology/allergy evaluation in an outpatient setting were subjected to both allergy testing and aerobic nasal culturing. Presenting complaints included chronic sinusitis, chronic and acute otitis media, chronic pharyngitis, and chronic or recurrent allergy symptoms involving the head and neck. Results were obtained for pathogen type and antibiotic sensitivity. Allergy testing employed the ImmunoCap™ IgE quantification for specific airborne and food allergies.

Results
54/130 (41.54 %) patient cultures were positive with S. Aureus (23) and S. Pneumoniae (10) being the most prominent. 40/54 (74.07%) of the patients with positive cultures were also positive for allergies. 20/40 (50%) of patients testing positive for both allergy and infection tested positively for S. Aureus. 16/25 (64%) Female patients with a positive culture grew S. Aureus, coagulase positive. Upon further adjusting to include allergy status, female patients with positive infection and positive allergy status had an even higher incidence of S. Aureus infection (15/21; 71.43%). Of 76 patients testing negative for bacterial infection, 28/76 (36.84%) of these patients tested positively for allergy. (Graphs PDF)

Conclusion
Allergy and bacterial infection are significantly correlated; patients with allergies had higher rates of infection than those without allergies. Women with an allergenic disease predisposition had the highest percentage of infection, with S. Aureus as the most commonly cultured pathogen. Although causality is hard to determine without insight into the basic science of allergy and its effects on the anatomy of the ears, nose, and throat, the relationship between allergy and bacterial infection seems to be clear and direct. After comparing to controls, allergy testing could help identify patients who are more susceptible to infection by certain microbes, particularly S. Aureus and S. Pneumoniae, and this supports the usage of allergy screening techniques to isolate those individuals at highest risk for infection. Better antimicrobial selection is achieved by further refining the clinician’s empirical understanding of possible pathogens.