Associations of IgE-mediated allergy and complicated appendicitis in adults

Introduction

The pathophysiological mechanisms behind appendicitis are not completely understood. Clinical and epidemiological studies have indicated that an individuals immune responses might propel the inflammation towards an uncomplicated or a complicated disease course. Our group has previously reported a protective association between IgE-mediated allergy and complicated appendicitis in children.

Methods

A retrospective cohort study of all consecutive patients >18 years of age treated for appendicitis at Skåne University Hospital, Malmö and Lund, Sweden, between 2022 and 2024. Associations of IgE-mediated allergy and complicated (gangrenous, perforated and appendicitis abscess) appendicitis were evaluated with univariate and multivariable logistic regression analyses with age, sex, symptom duration, presence of an appendicolith, and season of appendicitis as covariates.

Results

A total of 1518 patients were included, out of which 23% had IgE-mediated allergy. The proportion of complicated appendicitis cases did not differ significantly between the allergic and non-allergic patients. IgE-mediated allergy was not associated with the risk of appendicitis, neither in the univariate (OR 0.85 [95% c.i. 0.67–1.08], P = 0.182) nor the multivariable analyses (aOR 0.80 [95% c.i. 0.61–1.03], P = 0.088) with adjustment for age, symptom duration, and appendicolith status. The distribution of appendicitis cases was evenly distributed over the seasons among the non-allergic patients, while most allergy patients were treated for appendicitis during the spring and summer months (March-August).

Discussion

In this adult cohort, there was no significant association between IgE-mediated allergy and the risk of complicated appendicitis. This is in contrast to our previous finding in pediatric cohorts.

The seasonal incidence of appendicitis differs between allergic and non-allergic patients.