Dependence of immediate hypersensitivity on the month of birth

Clin Allergy. 1976 Mar;6(2):165-71. doi: 10.1111/j.1365-2222.1976.tb01894.x.


This report describes a retrospective study of 1421 patients allergic to pollens and 728 patients allergic to animal epithelia. In males, but not in females, the month-of-birth distribution differed significantly from that in the total population of Finland (P less than 0-01 in pollen allergy and P less than 0-05 in epithelium allergy). The phenomenon was most clearly apparent in boys aged 10-14 born in 1960-4 (P less than 0-01 in pollen allergy and P less than 0-001 in epithelium allergy). When the relative risk of immediate hypersensitivity was plotted as a function of the month of birth, a two-phasic curve with maxima in March-May and September-November was obtained for both pollen allergy and animal epithelium allergy. The results indicate that boys, but perhaps not girls, have a sensitive period early in life during which one or more environmental factor and seasonal variations in this factor influence the development of subsequent immediate hypersensitivity.

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Epithelium
  • Female
  • Finland
  • Humans
  • Hypersensitivity, Immediate / epidemiology*
  • Male
  • Pollen
  • Risk
  • Seasons