Background and objective: Having relatives with allergic disease is associated with an increased risk of such disease, but children without a significant genetic predisposition account for much of the increase in asthma prevalence. The aim of this study was to investigate whether the prevalence of a reported family history of allergy has increased among atopic respiratory patients diagnosed in Outpatient Service No. 3 in Tirana in recent decades.

Methods: We evaluated the records of 693 atopic respiratory patients sensitized to mites (n = 480) or pollen (n = 218) or both (n = 5) to detect reports of allergic disease among their close relatives. Patients were classified in 3 groups: those born in 1959 or earlier, those born between 1960 and 1979, and those born between 1980 and 2003. The χ2 test was used for statistical comparisons.

Results: The prevalence of a family history of allergy among those born before 1960 (42.7%) was nearly 2-fold greater than the prevalence among those born between 1960 and 1979 (25.3%) or between 1980 and 2003 (23.1%) (P < .001).

Conclusions: Younger generations of atopic respiratory patients report a family history of allergic disease about half as frequently as older ones. It is possible that massive introduction of antibiotics such as penicillin and streptomycin in the late 1960s and early 1970s for use against respiratory or gastrointestinal infections has increased survival for a considerable number of young children, switching the gene thesaurus of successive adult populations to an allergy-predisposing genotype.

Key words: Atopic diseases. Family history. Generations. Survival rate.