A large proportion of immunoglobulin E (IgE)-medi-ated food allergies in older children, adolescents and adults are caused by cross-reactive allergenic struc-tures. Primary sensitization is most commonly to in-halant allergens (e.g. Bet v 1, the major birch pollen al-lergen). IgE can be activated by various cross-reactive allergens and lead to a variety of clinical manifestations. In general, local and mild – in rare cases also severe and systemic – reactions occur directly a er consumption of the food containing the cross-reactive allergen (e. g. plant-derived foods containing proteins of the Bet v 1 family). In clinical practice, sensitization to the prima-ry responsible inhalant and/or food allergen can be de-tected by skin prick tests and/or in vitro detection of
speci c IgE. Component-based diagnostic methods can support clinical diagnosis. For individual allergens, these methods may be helpful to estimate the risk of
systemic reactions. Con rmation of sensitization by oral provocation testing is important particulary in the case of unclear case history. New, as yet unrecognized allergens can also cause cross-reactions.  etherapeutic potential of speci c immunotherapy (SIT) with inhalant allergens and their e ect on pollen-associated food allergies is currently unclear: results vary and placebo-controlled trials will be necessary in the future. Pollen allergies are very common. A ltogether allergic sensitization to pollen and cross-reactive food allergens are very common in our latitudes.  e actual relevance has to be assessed on an individual basis us-ing the clinical information