3. Fajt ML, Wenzel SE. Asthma phenotypes and the use of biologic medications in asthma and allergic disease: the next steps toward personalized care. J Allergy Clin Immunol. 2015; 135:299–310.
9. Simões SM, Cunha SS, Barreto ML, Cruz AA. Distribution of severity of asthma in childhood. J Pediatr (Rio J). 2010; 86:417–423.
10. Rabe KF, Vermeire PA, Soriano JB, Maier WC. Clinical management of asthma in 1999: the Asthma Insights and Reality in Europe (AIRE) study. Eur Respir J. 2000; 16:802–807.
13. Schatz M, Hsu JW, Zeiger RS, Chen W, Dorenbaum A, Chipps BE, et al. Phenotypes determined by cluster analysis in severe or difficult-to-treat asthma. J Allergy Clin Immunol. 2014; 133:1549–1556.
14. Mendes AP, Zhang L, Prietsch SO, Franco OS, Gonzáles KP, Fabris AG, et al. Factors associated with asthma severity in children: a case-control study. J Asthma. 2011; 48:235–240.
15. In Suh D, Song DJ, Baek HS, Shin M, Yoo Y, Kwon JW, et al. Korean childhood Asthma Study (KAS): a prospective, observational cohort of Korean asthmatic children. BMC Pulm Med. 2019; 19:64.
![crossref](/image/icon/bnr_ref_cross.gif)
16. Martinez FD, Vercelli D. Asthma. Lancet. 2013; 382:1360–1372.
17. Crapo RO, Casaburi R, Coates AL, Enright PL, Hankinson JL, Irvin CG, et al. Guidelines for methacholine and exercise challenge testing-1999. This official statement of the American Thoracic Society was adopted by the ATS Board of Directors, July 1999. Am J Respir Crit Care Med. 2000; 161:309–329.
18. American Thoracic Society. Standardization of spirometry, 1994 update. Am J Respir Crit Care Med. 1995; 152:1107–1136.
19. National Asthma Education and Prevention Program. Expert Panel Report 3 (EPR-3): Guidelines for the diagnosis and management of asthma-summary report 2007. J Allergy Clin Immunol. 2007; 120:S94–138.
20. Ha MN, Hong SJ, Won HS, Park HS, Kim YJ, Park EA, et al. Planning of cohort construction for children's growth and development research [Internet]. Seoul: National Institute of Health, Center for Genome Science;2006. cited 2019 Aug 13. Available from:
http://www.cdc.go.kr/CDC/cms/content/mobile/30/1230_view.html.
21. Liu AH, Zeiger R, Sorkness C, Mahr T, Ostrom N, Burgess S, et al. Development and cross-sectional validation of the Childhood Asthma Control Test. J Allergy Clin Immunol. 2007; 119:817–825.
22. Nathan RA, Sorkness CA, Kosinski M, Schatz M, Li JT, Marcus P, et al. Development of the asthma control test: a survey for assessing asthma control. J Allergy Clin Immunol. 2004; 113:59–65.
23. Small P, Kim H. Allergic rhinitis. Allergy Asthma Clin Immunol. 2011; 7:Suppl 1. S3.
![crossref](/image/icon/bnr_ref_cross.gif)
24. Weidinger S, Novak N. Atopic dermatitis. Lancet. 2016; 387:1109–1122.
25. Gupta RS, Springston EE, Smith B, Pongracic J, Holl JL, Warrier MR. Parent report of physician diagnosis in pediatric food allergy. J Allergy Clin Immunol. 2013; 131:150–156.
26. Miller MR, Hankinson J, Brusasco V, Burgos F, Casaburi R, Coates A, et al. Standardisation of spirometry. Eur Respir J. 2005; 26:319–338.
28. Hollenbach JP, Schifano ED, Hammel C, Cloutier MM. Exposure to secondhand smoke and asthma severity among children in Connecticut. PLoS One. 2017; 12:e0174541.
![crossref](/image/icon/bnr_ref_cross.gif)
31. Lanphear BP, Hornung RW, Khoury J, Yolton K, Lierl M, Kalkbrenner A. Effects of HEPA air cleaners on unscheduled asthma visits and asthma symptoms for children exposed to secondhand tobacco smoke. Pediatrics. 2011; 127:93–101.
32. Gong T, Lundholm C, Rejnö G, Mood C, Långström N, Almqvist C. Parental socioeconomic status, childhood asthma and medication use--a population-based study. PLoS One. 2014; 9:e106579.
36. Kim CK, Callaway Z, Gern JE. Viral infections and associated factors that promote acute exacerbations of asthma. Allergy Asthma Immunol Res. 2018; 10:12–17.
38. Mikalsen IB, Halvorsen T, Øymar K. The outcome after severe bronchiolitis is related to gender and virus. Pediatr Allergy Immunol. 2012; 23:391–398.
41. Holt PG, Sly PD. Viral infections and atopy in asthma pathogenesis: new rationales for asthma prevention and treatment. Nat Med. 2012; 18:726–735.
![crossref](/image/icon/bnr_ref_cross.gif)
42. Stein RT, Sherrill D, Morgan WJ, Holberg CJ, Halonen M, Taussig LM, et al. Respiratory syncytial virus in early life and risk of wheeze and allergy by age 13 years. Lancet. 1999; 354:541–545.
43. Tsukioka K, Toyabe S, Akazawa K. Relationship between asthma severity and age at onset in Japanese adults. Nihon Kokyuki Gakkai Zasshi. 2010; 48:898–905.
44. Wu TJ, Chen BY, Lee YL, Hsiue TR, Wu CF, Guo YL. Different severity and severity predictors in early-onset and late-onset asthma: a Taiwanese population-based study. Respiration. 2015; 90:384–392.
45. Lombardi C, Savi E, Ridolo E, Passalacqua G, Canonica GW. Is allergic sensitization relevant in severe asthma? Which allergens may be culprit? World Allergy Organ J. 2017; 10:2.
46. Medjo B, Atanaskovic-Markovic M, Nikolic D, Spasojevic-Dimitrijeva B, Ivanovski P, Djukic S. Association between pet-keeping and asthma in school children. Pediatr Int. 2013; 55:133–137.
47. Bacharier LB, Strunk RC, Mauger D, White D, Lemanske RF Jr, Sorkness CA. Classifying asthma severity in children: mismatch between symptoms, medication use, and lung function. Am J Respir Crit Care Med. 2004; 170:426–432.