Background: Skin prick tests and measurement of specific IgE are important markers of the possible causes of disorders of the upper respiratory tract.
Objective: In this study we investigated the association of skin test reactivity and specific IgE positivity to five common aeroallergens separately and of total serum IgE and eosinophil count with nasal allergy symptoms in a random sample of the adult population in the Netherlands.
Methods: A cross-sectional study was carried out in a sample of 2167 subjects, aged 20 to 70 years, stratified by age and gender. Nasal allergy symptoms were differentiated into three categories: symptoms after exposure to indoor allergens only, symptoms after exposure to outdoor allergens only, and symptoms after exposure to both indoor and outdoor allergens. Associations were investigated by multiple logistic regression analyses with adjustment for area of residence, gender, age, and smoking status.
Results: Skin test and specific IgE reactivity to indoor and outdoor allergens were significantly related to their corresponding nasal symptom groups. Odd ratios increased with increasing number of positive skin test results or increasing levels of specific IgE to allergens in all three nasal symptom groups. For each allergen, a positive skin test result together with a positive specific IgE measurement were the strongest predictors of nasal symptoms. Sensitization to house dust mite was the most prevalent in our study population, whereas the association of skin test reactivity and specific IgE positivity with nasal symptoms was strongest for cat allergen. Skin test and specific IgE reactivity to Cladosporium species were not significantly related to the prevalence of nasal symptoms. Total serum IgE was related to nasal symptoms only in subjects who reported symptoms in response to both indoor and outdoor allergens and only at high levels of IgE. Eosinophil count was associated with nasal symptoms in all nasal symptom groups.
Conclusion: Our findings confirm the close relationship of skin test positivity with reported symptoms of nasal allergy in a general population. Specific IgE positivity also shows a close relationship with nasal symptoms in response to allergen exposure in a general population. Skin testing and specific IgE measurement may be considered complementary to one another in diagnosing allergic rhinitis. Total IgE may be considered an indicator of greater dysregulation of the immune system in atopic allergy. Eosinophil count is associated with nasal symptoms, regardless of type and extent of nasal symptoms.