Prevalence and early-life risk factors of school age allergic multimorbidity - the EuroPrevall-iFAAM birth cohort

BACKGROUND: Coexistenceofchildhoodasthma,eczemaandallergicrhinitisishigherthancanbeexpectedbychance,suggestingacommonmechanism.Dataonallergicmultimorbidityfromapan-European,population-basedbirthcohortstudyhasbeenlacking. This study compares the prevalence and early-life risk factors of these diseases in European primary school children.METHODS: IntheprospectivemulticentreobservationalEuroPrevall/iFAAMbirthcohortstudyweusedstandardizedquestionnairesonsocio-demographics,medicalhistory,parentalallergiesandlifestyle,andenvironmentalexposuresatbirth,12and24months.Atprimaryschoolage,parentsansweredISAAC-basedquestionsoncurrentasthma,rhinitisandeczema.Allergicmultimorbiditywasdefinedasthecoexistenceofatleasttwoofthese.RESULTS: From10,563childrenrecruitedatbirthin8studycentres,weincludeddatafrom5,572children(meanage8.2years;51.8%boys).Prevalenceestimateswere:asthma8.1%,allergicrhinitis13.3%,eczema12.0%.Allergicmultimorbiditywasseenin7.0%ofthewholecohort,rangingfrom1.2%(Athens,Greece)to10.9%(Madrid,Spain). Riskfactorsforallergicmultimorbidity, identified with AICc,includedfamily-allergy-score, oddsratio(OR)1.50 (95% CI 1.32-1.70)perstandarddeviation;early-lifeallergysymptoms, OR2.72 (2.34-3.16)foreachsymptom;andcaesareanbirth, OR1.35 (1.04-1.76).Femalegender, OR0.72 (0.58-0.90);oldersiblings,OR0.79 (0.63-0.99);andday-care, OR0.81 (0.63-1.06)wereprotectivefactors.CONCLUSION: AllergicmultimorbidityshouldberegardedasanimportantchronicchildhooddiseaseinEurope.Someoftheassociatedearly-lifefactorsaremodifiableandmaybeconsideredforpreventionstrategies.</p