PurposeAllergic rhinitis (AR) is common among children with asthma and exacerbates asthma symptoms. To assess the incremental utilization and cost of asthma-related health services due to concomitant AR among asthmatic children.Materials and MethodsAsthma-related claims were extracted from the Korean National Health Insurance (NHI) claims database, which covers 97% of the population. Per-capita utilization and costs of asthma-related services were determined from the societal perspective.ResultsOf 319,714 children (1 - 14 years old) with chronic asthma in 2003, 195,026 had concomitant AR (prevalence 610 per 1,000 asthmatic children). Children with AR had 1.14 times more outpatient visits, 1.30 times more emergency department (ED) visits, and 1.49 times more hospitalizations than children without AR. More children with AR used general hospitals (7.17%) than children without AR (3.23%). The ratios of unit pharmaceutical costs per outpatient visit, ED visit, and admission between children with and without AR were 1.27, 1.20, and 1.14. Total annual expenditure combining direct health care, transportation, and caregivers' costs, were $273 and $217 for children with and without AR, respectively.ConclusionHealth service utilization and costs for asthma were greater for asthmatic children with AR. More frequent ED visits and admissions among asthmatic children with AR suggest poorer control and more frequent exacerbations. Higher unit cost of pharmaceuticals during visits, tendency to receive asthma care from a higher-level facility, and greater risk of ED visit or admission all contributed to the additional economic burden of AR.