“Genetic and environmental factors as well as pathologic alterations of the microbiota in the appendix have been identified as potential risk factors,” Jacob Antonsen, of the digestive disease center at Bispebjerg Hospital in Denmark, and colleagues wrote. “Several studies have shown an altered composition of the microbiota in specimens of appendicitis, but it remains unclear whether the microbial changes are a trigger or a consequence of appendicitis.”
Researchers performed a cohort study from 1995 to 2014 comprising 1,385,707 children who received 7,406,397 antibiotic prescriptions. The primary outcome of the study was appendicitis requiring appendectomy according to previous use of antibiotics.
In the study cohort, there were 11,861 cases of appendicitis.
Children who received at least one course of antibiotics were at increased risk for developing appendicitis compared with children who were not exposed to antibiotics (adjusted RR = 1.72; 95% CI, 1.61-1.85). The risk ratio increased by 1.04 per course of antibiotics.
Children exposed to antibiotics in the first 6 months of life (RR = 1.46; 95% CI, 1.36-1.56) and children exposed to broad-spectrum antibiotics (RR = 1.33; 95% CI, 1.27-1.39) had a higher risk for appendicitis. However, the association disappeared after researchers adjusted for number of antibiotic courses.
“This nationwide cohort study shows a dose-response relationship between antibiotic exposure and the development of appendicitis in childhood and adolescence,” Antonsen and colleagues wrote. “Further research will need to clarify whether antibiotics are causally involved in development of appendicitis or if some children are more prone to acquiring bacterial infections, including appendicitis, and therefore have a high exposure to antibiotics.”