Inconsistent Skin Prick Tests for Allergy to Birch Homologous Trees May Result from Cross-Reacting Allergens or Technical Errors.

INTRODUCTION: Skin prick tests (SPTs) are the gold standard for diagnosis of allergic rhinitis (AR). A decrease in the number of allergens included in standard SPT panels has recently been debated - particularly regarding the cross-reacting homologous pollen from birch, alder, and hazel trees - but has not yet been implemented in clinical guidelines. METHODS: A subgroup of patients with AR (n = 69) who showed inconsistent SPT results among birch, alder, and hazel was investigated in detail. Beyond SPT, patient workup included assessment of clinical relevance and various serological parameters (total IgE, and specific IgE to birch, alder, and hazel and to Bet v 1, Bet v 2, and Bet v 4). RESULTS: More than half the study group had negative SPT results for birch but positive results for alder and/or hazel, and 87% of the study group was polysensitized, showing at least one more positive SPT result for other plants. Whereas 30.4% of patients showed serological sensitization to birch pollen extract, only 18.8% displayed positive specific IgE to Bet v 1. Clinical assessment revealed that most patients with AR were polysensitized and had perennial symptoms or symptoms also occurring during times other than tree flowering times. If the SPT panel is limited to testing birch only, 52.2% of patients in this subgroup would have been overlooked. CONCLUSION: Inconsistent SPT results in the birch homologous group may result from cross-reacting allergens or technical errors. If patients report convincing clinical symptoms despite negative results from a reduced SPT panel or inconsistent results for homologous allergens, SPT should be repeated, and molecular markers should be added to achieve a correct diagnosis.

Immunoglobulin E-Mediated Food Allergies Differ in East Mediterranean Children Aged 0-2 Years.

OBJECTIVE: Precise diagnosis of allergy requires knowledge of the population's food allergy (FA) spectrum and predictors. METHODS: Medical charts of Turkish children aged 0-2 years with FA and/or atopic dermatitis (AD) were reviewed. RESULTS: A total of 1,389 patients, 912 with FA and 1,140 with AD, were included. In the FA group, the most frequently diagnosed FAs were egg white (75.9%), cow's milk (55.7%), tree nuts (31.5%) and sesame (20.6%). The detection of FA in 99% of children with any kind of FA necessitate testing with egg white, cow's milk, hazelnut, sesame, walnut, cashew, and pistachio. In the FA group, 72.7 and 56.8% had AD and multiple FA respectively. Multiple FA (56.8 vs. 49.8%) and hen's egg allergy (85.5 vs. 50.2%, p < 0.005) were more common and cow's milk allergy (51.4 vs. 67.1%, p < 0.005) less common in the AD subgroup of the FA group than in the non-AD subgroup. Multiple FA likelihood increases parallel to the severity of AD (p < 0.05). In the AD group, 58.2% had an immunoglobulin E-mediated FA. The risk of concomitant FA increased as the age at symptom onset of AD decreased (OR 0.800 [95% CI 0.731-0.875]; p < 0.001) and the severity of AD increased (OR 2.350 [95% CI 1.898-2.911]; p < 0.001). CONCLUSION: Although severe and early-onset AD is a predictor of the presence and magnitude of FA in infancy, the spectrum of FA is a reflection of cultural characteristics. The clinical presentations of both AD and FA may in fact be an expression of the extent of the immune dysregulation underlying atopy and allergy.