The relationship between allergic sensitization and radiographic sinus inflammation remains unclear. To determine whether specific allergen sensitization is correlated with sinonasal radiographic opacification. Patients with chronic sinonasal symptoms were selected and included if they had allergy testing and a computed tomography (CT) of the paranasal sinuses. Data regarding demographic characteristics, in vitro allergy test results, and comorbidities were collected. CTs were reviewed, and an overall Lund-Mackay score (LMS) was calculated for each patient. A two-sample t-test was used to compare mean LMS between patients who were sensitized and patients who were not sensitized. A multiple linear regression model was used to determine whether a relationship existed among LMS and allergy results, asthma, nasal polyps, immunoglobulin E (IgE) level, medication usage, in-season versus out-of-season CTs, age, and sex. Significance was determined at an alpha level of 0.05. There were 437 patients included, of whom, 251 had positive specific allergen test results and 186 had negative test results. A total of 282 patients had allergic rhinitis symptoms without a documented diagnosis of sinusitis, and 155 carried a diagnosis of chronic rhinosinusitis. The mean LMS did not differ between patients who were sensitized and patients who were not sensitized (5.56 versus 5.28; p = 0.61). Linear regression demonstrated an increase in LMS in patients with asthma (p = 0.02), male sex (p < 0.01), elevated IgE (p < 0.01), a history of anaphylaxis (p = 0.03), and nasal polyps (p < 0.01). There was a statistically significant decrease in LMS in patients with an in-season CT (p = 0.02). Patients with a positive specific in vitro allergen test result did not have higher overall rates of radiographic sinus inflammation. Asthma, male sex, polyps, elevated IgE, and a history of anaphylaxis were associated with higher LMS.