This study investigates the seasonal and regional distribution of paediatric laryngomalacia admissions in the United States, hypothesizing higher admission rates in winter and colder regions due to reduced sunlight exposure affecting vitamin D levels.

We analyzed data from the 2016 Kids’ Inpatient Database (KID), focusing on children under three years old. Laryngomalacia cases were identified using International Classification of Diseases and Related Health Problems 10th Revision (ICD-10) code Q31.5. Seasonal and regional differences in admission rates were assessed using Pearson’s chi-squared test, with a significance level of p less than 0.05.

Of 4,512,196 estimated national admissions, 11,638 were due to laryngomalacia. Admissions increased by 10.0 per cent in winter and decreased by 10.9 per cent in summer (p < 0.005). Regionally, admissions were higher in the Midwest/Central (18.6 per cent) and Northeast (9.3 per cent) and lower in the South (7.4 per cent) and West (11.1 per cent) (p < 0.005).

Laryngomalacia admissions are significantly influenced by seasonal and regional factors, likely related to environmental conditions affecting vitamin D synthesis.