(209) Comorbid Conditions Associated With External Auditory Canal Dermatitis: A Retrospective Matched Case-Control Study

Introduction: External auditory canal (EAC) dermatitis is a common yet understudied condition in otolaryngology. While often attributed to local irritation, its associations with dermatologic, allergic, otologic, and systemic comorbidities remain poorly characterized. This study examined comorbidity patterns, diagnostic evaluation, and management features of patients with EAC dermatitis compared with matched controls.

Methods: A retrospective matched case–control study was conducted from 2010–2025 at a tertiary academic medical center. Cases were matched to controls by encounter timing, age, race, and sex. Sociodemographic data and systemic, dermatologic, allergic, and otologic comorbidities were collected.

Results: The cohort included 680 EAC dermatitis cases and 680 controls. Overall comorbidity burden, measured by the Charlson Comorbidity Index, showed no statistically significant association with EAC dermatitis (OR 0.97, 95% CI 0.92–1.02; p = 0.21). Conditional logistic regression showed increased odds of EAC dermatitis among patients with a history of eczema (OR 5.03, 95% CI 1.81-13.95; p = 0.019), and allergic rhinitis (OR 2.54, 95% CI 1.02-6.33, p=0.045). No significant associations were observed for diabetes, chronic pulmonary disease, or cardiovascular disease.

Conclusions: These findings suggest that EAC dermatitis is associated with specific comorbidity patterns, underscoring the importance for otolaryngologists to consider both cutaneous and systemic health factors when evaluating affected patients. This work provides a foundation for improved risk stratification and more targeted, dermatology-informed management strategies in otolaryngologic practice.