Pollen allergens of the Poaceae family comprise one of the main causes of pollinosis worldwide. Although most of cereals are included in this family, certain pollination characteristics and aerobiological features differentiate them from common wild grass pollen. Cereal pollen grains cannot be easily characterised as potential sources of aeroallergens, because of their pollination mode (most of them are autogamous plants), the consecutive low numbers of pollen they produce and their pollen's large volume and consequent high weight which further prevent dispersion and pollen transport. However, various epidemiological studies concluded in comparable sensitisation patterns between common grass and cereal pollen. This fact can be attributed to the common epitopes shared between grass and cereal pollen allergens, which are responsible for the high cross reactivity observed not only in vitro but also in vivo. Therefore, the sensitisation patterns do not usually reflect a genuine, cereal-specific IgE recognition. On the contrary, genuine cereal sensitisation and allergy are referred to only in rare cases of occupational exposure to high amounts of these pollen grains (farmers and field workers) or in patients staying in the vicinity of cereal fields. Thus, cautious considerations should be taken into account when diagnostically approaching patients in which cereal pollen allergy could be considered in the differential diagnosis.
FULL TEXT