Sensitization to cereals and peanut evidenced by skin prick test and specific IgE in food-tolerant, grass pollen allergic patients

70 subjects (41 females; mean age 32 years) and 20 healthy controls (13 females; mean age 24 years) were tested by open food challenge (OFC) with cereals and peanut. SPT and sIgE both with Immulite？ (Siemens) and ImmunoCAP？ (Phadia) to grass and birch pollen, cereals, peanut and bromelain were performed.Of the 65 OFC-negative subjects 29-46% (SPT, depending on cut-off), 20% (Immulite) and 38% (ImmunoCAP) had positive results to one or more of the foods tested. Controls were negative in all tests. Cross-reactive carbohydrate determinants (CCD) as evidenced by reaction to bromelain could explain only a minority of the measured IgE-sensitizations.Grass pollen allergic patients with documented food tolerance to cereals and peanut may express significant sensitization. False-positive cereal or peanut allergy diagnoses may be a quantitatively important problem both in routine clinical work and epidemiological studies.Wheat IgE-mediated allergy manifests itself as food allergy [1] and as occupational inhalant allergy (Baker's asthma) [2] and identical allergens seem to be responsible in both allergies, although their relative importance differ [3,4]. It is a general clinical experience that also patients without these diseases may display positive skin test or immunoglobulin E (IgE) towards wheat and the cross-reactivity between grass pollen and cereals may have an impact on the specificity of the diagnostic tests [1,5-7].In a non-published retrospective study performed in our department we found a large number of positive reactions to cereals in specific IgE (sIgE) tests in grass pollen allergic patients claiming to tolerate cereals, when interviewed by telephone. Also Jones et al. [8] found clinically non-relevant reactions to cereals in grass pollen allergic patients. Low specificity of cereal-related diagnostic tests is a particular problem since grass pollen allergy is very prevalent compared to true cereal allergy, but studies of grass pollen allergic subjects with c