ABSTRACT
PURPOSE: An increase in the incidence of pediatric complicated appendicitis (CA) during the COVID-19 pandemic has been reported in many countries. We investigated how the pandemic has affected Japan. METHODS: We retrospectively reviewed children of ≤ 15 years old treated for acute appendicitis across 5 medical centers during the pandemic period (January to October in 2020), with the pre-pandemic period (January to October in 2017 to 2019) evaluated as a historical control. The incidence of CA and disease characteristics were then compared between the periods. RESULTS: The total number of patients was 55 in 2020 and 192 in 2017-2019. In all centers, the incidence of acute pediatric CA in the pandemic period significantly increased compared to the pre-pandemic period (18.2% vs. 32.7%, p = 0.02). On limiting our evaluation to the 3 institutions with reductions in patient numbers, the incidence of CA increased (16.3% vs. 37.9%, p = 0.01), and the duration of pre-operative symptoms was prolonged (1.3% vs. 1.7 days, p = 0.03). There were no significant differences in the age, sex, white blood cell count, C-reactive protein, or body temperature. No cases were diagnosed with SARS-CoV-2. CONCLUSIONS: The incidence of acute pediatric CA increased during the pandemic period. This may be related to an extended duration of symptoms due to individuals fearing contracting COVID-19 while visiting a hospital.