title: Skin reactivity to histamine and codeine in unselected 9-year-old children from Italy, Poland and Libya.
abstract: BACKGROUND
  Previous studies have shown that histamine skin reactivity (the dimensions of a skin wheal elicited by a prick with histamine 10 mg/ml) in unselected school children has increased in Italy during the past two decades and is higher in Italy than in Poland. Hence this variable can probably be influenced by a changing or different lifestyle. The aim of this study was to compare skin reactivity to histamine and codeine (a marker of histamine releasability from mast cells) in schoolchildren from countries with different lifestyles.
  
  
  METHODS
  Six previously unstudied unselected populations of 9-year-old schoolchildren (two each from Poland, Italy, and Libya; n = 863 subjects; 49.0% males) were pricked with two concentrations of histamine (10 and 1 mg/ml) and codeine (90 and 9 mg/ml).
  
  
  RESULTS
  The higher concentrations of both pharmacologic agents tested yielded significantly different wheal areas in the three countries: Poland < Italy < Libya (histamine, 11.8, 16.1 and 20.7 mm2; codeine, 9.2, 13.2 and 16.2 mm2; p < 0.001 for all comparisons). The lower concentrations elicited almost matching results. Histamine wheal areas correlated closely with areas elicited by codeine in the same individual: angular coefficients of the histamine to codeine regression lines were 0.535, Italy; 0.551, Libya; 0.612, Poland; and 0.581 for the whole population. More histamine was needed to produce a wheal in Poland than in Libya: a 20-mm2 wheal required an injected histamine concentration of about 8.8 mg/ml in Libya, 29.5 mg/ml in Italy and 102.1 mg/ml in Poland.
  
  
  CONCLUSIONS
  More studies are necessary to explain the observed international differences in skin histamine reactivity and their effect on the prevalence of positive allergen skin tests.
authors.affiliation: Department of Pediatrics, Second School of Medicine, University La Sapienza, Rome, Italy. ronchetti@uniroma1.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Ronchetti
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Villa
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Bohmerova
authors.forename: Susy
authors.initials: S
authors.lastname: Martella
authors.forename: Carlo
authors.initials: C
authors.lastname: Falasca
authors.forename: Mario
authors.initials: M
authors.lastname: Barreto
authors.forename: Anna
authors.initials: A
authors.lastname: Lesiak-Bednarek
authors.forename: Ahmed
authors.initials: A
authors.lastname: Al-Bousafy
authors.forename: Abdulhamid
authors.initials: A
authors.lastname: Al-Tubuly
authors.forename: Jacek
authors.initials: J
authors.lastname: Zakrzewski
authors.forename: Janusz
authors.initials: J
authors.lastname: Haluszka
mesh_terms: D002648:Child; D003061:Codeine / Q000276:immunology*; D005260:Female; D006632:Histamine / Q000276:immunology*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology* / Q000276:immunology*; D007558:Italy / Q000453:epidemiology; D008002:Libya / Q000453:epidemiology; D008297:Male; D011044:Poland / Q000453:epidemiology; D012867:Skin / Q000276:immunology*; D012882:Skin Tests
chemical_list: D006632:Histamine; D003061:Codeine