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Wise et al.

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this association seemed to weaken with an OR estimate for AR among subjects with low SES changing from 0.79 to 0.92.

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In 2000, an article was published from the German Multicentre Allergy Study (MAS) birth cohort including 1314 children born in 1990. 610 In this study, it was found that the lifetime prevalence of hay fever was elevated in parents of high SES compared to low. However, in their children, the occurrence of hay fever was not elevated in families with high SES. Alternatively, in the Swedish birth cohort BAMSE (Swedish abbreviation for Children Allergy, Milieu, Stockholm, Epidemiology) with 4089 children born between 1994 and 1996, it was noted that high SES actually resulted in a decreased risk of AR, along with decreases in asthma and food sensitization rates. 611 In a recent study from Denmark of 9720 children born between 1994 and 2006, AR was associated with low educational level of the parents. 612 Interestingly, in the follow-up of the German MAS birth cohort study, SES was not associated with AR at all by the age of 20 years. 613 Thus, among children born in the Western world before 1970 high SES was a risk factor, but among children born in the same regions after 1990 low SES, particularly early in life, seemed to be a risk factor 614 (Table VI.F). More recently, 2 studies from Korea have reconfirmed the previously noted association between high SES and the development of AR. Ahn et al. 478 found a positive association between higher family income and symptom-based AR diagnosis (but not allergy test-based AR diagnosis). Lee et al. 615 also found family affluence, or high SES, to be a significant risk factor for AR in Korean adolescents. However, additional recent studies from South America and Europe have shown varying results. In 2016, Penaranda et al. 616 found high SES to be associated with AR in children/adolescents but not in adults, while Wronka et al. 617 identified a significantly higher incidence of AR in adult female university students (19 to 25 years old) from families with high SES. Overall, SES is likely a proxy for various exposures like number of siblings, viral infections, exposure to tobacco smoke, housing conditions and location, allergen exposures, dietary factors, and nutrition including breastfeeding and general diet. Some of those exposures are associated with the hygiene hypothesis, introduced by Strachan 618 in the late 1980s. However, it is worth noting that exposures relevant to the hygiene hypothesis were important predictors for the development of AR at an early age. 614 Currently, there is conflicting evidence regarding the association between SES and AR. While most studies show an association between high SES and the diagnosis of AR, this is not a consistent outcome. This disparity may be explained by the additional factors evaluated in several of these studies which may confound the exact relationship between SES and AR. Additionally, there may be a temporal relationship between SES and AR considering different outcomes in children compared to adults. Additional investigation is needed to determine the true relationship between AR and SES. • Aggregate Grade of Evidence: C (Level 2b: 4 studies; Level 4: 6 studies; Table VI.F).

Int Forum Allergy Rhinol . Author manuscript; available in PMC 2020 June 10.