Pediatric appendicitis may be co-associated with meteorologic factors: A case-crossover study.

Background: The etiopathogenesis of appendicitis is still not fully understood. Few reports have researched the impact of weather as a cofactor for the development of appendicitis.

Methods: To investigate the potential association between the development of appendicitis and exposure to ambient meteorological conditions, a retrospective case-crossover study was conducted. Publicly available meteorologic data were matched with those from 1343 patients aged ≤19 years with histologically confirmed acute (AA; n = 996) or perforated appendicitis (PA; n = 347) treated at our pediatric surgical hospital between October 2001 and October 2018.

Results: A time-stratified conditional logistic regression analysis revealed increased odds ratios (ORs) for AA of 4-5% for each 1 hPa increase in vapor pressure during each 3-7 day cumulative moving averages (CMA) lag preceding appendectomy. This effect was stronger on stratification by age class >10 years (OR 1.05-1.08; 3-7-day CMA) and during spring (OR 1.08-1.09; 4-7-day CMA). Moreover, each 1% increase in relative humidity on the day of appendectomy was associated with a 2% decrease in the OR for PA, which was 4% during autumn under seasonal stratification.

Conclusion: The role of meteorologic factors in the development of appendicitis remains largely unclear. In accordance with the literature, our results show that seasonal variations together with exposure to altered levels of humidity and vapor pressure may impact patients at different grades of appendiceal inflammation. Thus, transient fluctuations in meteorologic and seasonal variables may constitute cofactors that potentially influence the occurrence and course of pediatric appendicitis.