职称英语《卫生类A级》考试教材新增2015年职称英语《卫生类A级》考试教材新增完形填空第十二篇TheEnemyWithinAllergyhasbecomemoreandmorecommonoverthelast30years.Nowone-thirdofusareaffectedbyallergyatsomepointinourlivesandhalfofthesesufferersarechildren.IntheUK,threemillionpeoplesufferfromasthma,andfivepercentofchildrensufferfromfoodallergy.Allergyisareactionthatoccurswhentheimmunesystemhasastrangeandunnecessaryreactiontoasubstancewhichisnormallyharmless,suchaspollenorpeanuts.____1____Todefendyourbodyagainstanattacker,theimmunesystemremembersthesedangerousmicro-organismsandattacksthemifitmeetsthemagain.Thisworkisdonebyantibodies.Theimmunesysteminallergysufferersmakesantibodiesagainstharmlesssubstances,becauseitmistakenlybelievesthemtobedangerous.Anallergicreactionmaynothappenthefirsttimeasufferermeetsanallergen(thesubstancecausingthereaction,suchaspollen,milkorstrawberries).Sometimespeoplecaneatnutsforyearsandthensuddenlybecomeallergictothem.Whathashappenedisthattheimmunesystemhasnowdecidedthesubstanceisdangerousandhasmadeanallergyantibody.Thisantibodythenattachesitselftocells,whichcontainhistamine.____2____Astheydothat,thesurfaceofthecellsisbroken,andhistamineisreleased.Thehistamineandotherchemicalsinflamethetissues.Thisleadstothesymptomsofallergy,suchasswelling,rashes,sneezing,soreeyesandbreathlessness.Anaphylaxisisthemostsevereallergicreactionofallandismostoftentriggeredbywasporbeestingsorpeanuts.Thismustbetreatedimmediately.____3____Somepeoplearebornwiththeabilitytomakelotsofallergyantibodies,andtheyaremorelikelytodevelopallergiesandallergicdisorderssuchashayfeverandasthma.____4____Weeatmoreprocessedfoods,withawiderangeofadditivesandcolourings;moreandmorepeoplehavecentralheatinganddoubleglazing,makingourhouseswarmerandlessdraughty-anidealenvironmenttobreedthehousedustmite.Theremayalsobealinkbetweenallergiesandantibiotics.Atonetimeourimmunesystemswerekeptbusyfightingoffdiseaseandtryingtowinthebattleforhealth,butantibioticshavereducedtheamountofworkourimmunesystemshavetodo.Nowexpertsthinktheymaydirectsp