Prevalence and allergen of allergic rhinitis in Korean children.

BACKGROUND: In recent decades, the amount of data about allergic rhinitis (AR) in Korean National Health Insurance Service has increased. OBJECTIVE: To investigate the prevalence and quality of sensitized allergens of AR in Korean children and adolescents. METHODS: This study obtained the results of the Korean International Study of Asthma and Allergies in Childhood questionnaires and the skin-prick test (SPT) results of 14,356 students who participated in a health screening from 2010 to 2014. AR was defined as one with current symptoms of AR with at least one or more positive results of an SPT with inhalant allergens. RESULTS: The prevalence of AR in children was 20.8%. Positive rates of the allergen group were 87.3% for house-dust mites, 37.0% for pollen, 12.4% for mold, and 8.4% for pets. The common allergens in descending order were Dermatophagoides pteronyssinus, Dermatophagoides farinae, Betula, Humulus, Alnus, and Alternaria. As the children became older, pollen-sensitization rates tended to increase (p value for trends, <0.001). In metropolitan and middle inland areas, weed pollen was the most common pollen. The rates of tree-pollen sensitization were the highest at the seaside and in the southern inland. The most common comorbid allergic diseases associated with AR were pollen allergy and allergic conjunctivitis at 37.0% and 34.5%, respectively. CONCLUSIONS: This was the first study conducted in Korea to investigate the prevalence of AR in the general population by using both questionnaires and SPTs. The allergens used for the SPTs were chosen based on the common allergens in this study, and this current pollen data will contribute to establish the cause of increasing AR prevalence in Korea.

The effect of Asian dust on asthma by socioeconomic status using national health insurance claims data in Korea.

CONTEXT: Asian dust events are associated with increased asthma incidence, asthma exacerbation, decreased lung function and increased risk for hospitalization. OBJECTIVE: The purpose of this study was to evaluate the effect of Asian dust events on asthma exacerbation by socioeconomic status using national health insurance claims data. MATERIALS AND METHODS: A case-crossover design was used to analyze asthma-related national health insurance claims, air pollutant and climate data from 2007 to 2013 in Seoul and Incheon, Korea. We stratified our analysis by socioeconomic status (health insurance versus medical aid subscribers) and calculated the maximum air pollutant levels and average climate values per day. The number of asthma-related visits to medical institutions per day was compared between "event" and "control" days. RESULTS: Compared with "control days", the average number of asthma-related visits to medical institutions decreased on "event" days and increased 1-5 d thereafter. The number of visits by health insurance subscribers also decreased on "event" days and increased 1-5 d thereafter, while the number of visits by medical aid subscribers did not change on "event" days but increased 1-4 d thereafter. DISCUSSION AND CONCLUSION: Our study confirms that Asian dust events result in an increased number of asthma-related visits to medical institutions. This effect differed by socioeconomic status.