Clustering of foodstuffs in food hypersensitivity. An inquiry study in pollen allergic patients.

600 pollen allergic patients were questioned about hypersensitivity symptoms from various foodstuffs. The answers regarding one foodstuff were compared with those of other foodstuffs making 780 tables, from which the Spearmen 's correlation coefficients were calculated. Most of the combinations of foodstuffs showed statistically significant correlations. The highest value of the correlation coefficient was found for certain combinations: Various nuts reciprocally as well as nuts combined with apple and stone fruits. Stone fruits reciprocally and even stone fruits combined with apple and pear. Apple and pear. Kiwi fruit and avocado. Potato and carrot. Swede , parsnip and celery reciprocally. Strawberry and wild strawberry. Fish and bread, fish and cheese. Beer and wine. Several of the foodstuffs showing high degrees of correlation are known to be associated with birch pollen allergies. It is probable that at least some of these correlations are due to true IgE-mediated cross-reactivity with common allergens in birch pollen and foodstuffs. Other, hitherto less well understood mechanisms, might be at work as well. It is concluded that clustering of foodstuffs is common in food hypersensitivity and that in Sweden this phenomenon mostly is due to the association between birch pollen and some foodstuffs.