Nasal mucosal histamine reactivity among young students

Office workers (1, 2), school personnel (3, 4) and thegeneralpopulation(5,6)commonlycomplainaboutpoorindoorairquality.Manystudieshaveshownarelation-ship between staying in damp buildings and irritativesymptoms from the mucous membranes of the airways(7,8).The indoor environment is also one of many factorsdiscussedascontributingtoanincreaseintheprevalenceof atopy in western industrialized countries, mainly inyoung people (9). However, it is probably much lessimportant than a lower exposure to bacterial infectionsandchangesineatinghabitsearlyinlifeconnectedwiththewesternlifestyle(10–12).Many houses built during the last few decades areairtight and poorly ventilated.Irritatingvolatile organicand inorganic compounds in the indoor air may, undertheseconditions,emanatefrombuildingmaterialsandactas adjuvant factors for allergic sensitization (13, 14). Ahigh level of indoor humidity may also provide optimalconditions for the growth of mites and allergy to them(15,16).IgE-mediated diseases of the airways (asthma andrhinitis) are usually accompanied by a contemporaryhyperresponsivenesstonon-allergicstimuli,suchascoldair,dustandvariousirritants(17,18).Itseemslikelythatanallergicinflammationaffectsthemucosal sensory nerves, which become hyperreactive(19). However, some studies also indicate a mucosalhyperresponsiveness out of season in patients sufferingfromseasonalallergytopollen(20,21).Background:Inastudyperformedinthespringof1995,wefoundasignificantlygreaternasalmucosalhistaminereactivityamongteachers,whohadworkedforseveralyearsinarecentlyrenovatedmoisture-damagedschool,thaninthoseinacontrolschool.Inthepresentstudyweinvestigatedthestudentswhobeguntheirhigh-schoolstudiesatbothschoolsintheautumnof1995andcomparedthemwiththeteachersasregardsmucosalreactivity,atopyandsymptoms.Methods:Twenty-eightteachersinthetargetschool,18teachersinthecontrolschooland45studentsfromeachschoolunderwentanasalhistamineprovo-cationtestandaskin-pricktest.Theyalsoansweredastandardizedquestion-naire.Results:Theteachersinbothschoolshadmoremarkednasalmucosalhistaminereactivityatthelowestprovocationconcentrationsthanthestudents.Thehis-tamineprovocationcurveofthetargetschoolteachershadconsistentlyhighervaluesthanthatofthestudents(P ¼ 0.0001),butitsslopeandshapeweresimilar(P ¼ 0.15),whiletheslopeoftheprovocationcurveofthecontrolschoolteacherswasflatter.However,therewasonlyaborderlinesignificanceinthisrespectcomparedtothestudents(P ¼ 0.07).Teacherswithadryandcrustyappearanceofthenasalmucosaonanteriorrhinoscopyreactedmorestronglytohistamineprovocationthanthosewithoutthisfinding(P ¼ 0.0004).Therewasasignificantlyhigherfrequencyofskin-pricktestpositivity(SPT+)amongthestudents(P ¼ 0.03).Therewerenosignificantdifferencesinnasalmucosalhis-taminereactivitybetweenatopicandnon-atopicsubjectsoutofpollenseason.Conclusions:Teachershadasignificantlygreatermucosalhistaminereactivitythanthestudents,whereasthelatterhadasignificantlyhigherfrequencyofatopy.Theseresultsarecompatiblewithanage-relatedpatternofmucosalreactivity.Acrustyappearanceofthenasalmucosaseemstopredisposetoanincreaseinhistaminereactivity.Therewerenosignificantdifferencesaccordingtohistaminereactivitybetweenatopicandnon-atopicsubjects.S.Rudblad