I've wondered too. Very similarly in Turkey - growing up I'd never even heard of anyone with serious allergies to anything really, except perhaps seasonal aller

I've wondered too. Very similarly in Turkey - growing up I'd never even heard of anyone with serious allergies to anything really, except perhaps seasonal allergies, which mostly meant a runny nose. Certainly I'd never seen an epi-pen in my life, and no allergies people took serious medication or did immunotherapy for. Do we have a proper explanation for this? edit: one study citing a need for more data: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3879010/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3879010/ another old article (2011) on the Hygiene Hypothesis: https://www.nature.com/nature/journal/v479/n7374_supp/full/479S2a.html?foxtrotcallback=true https://www.nature.com/nature/journal/v479/n7374_supp/full/4...