Allergen-specific immunoglobulin E in the skin and nasal mucosa of symptomatic and asymptomatic children sensitized to aeroallergens.

BACKGROUND Asymptomatic sensitization is confirmed by a positive response to skin prick tests (SPT) with allergens in the absence of clinical symptoms of allergy. This is a common observation for which no convincing explanation has been provided.We investigated the extent to which the presence of specific immunoglobulin (Ig) E in the nasal mucosa accounts for the occurrence of symptoms. METHODS The study population comprised 192 patients with positive SPT results to aeroallergens: 111 had symptomatic allergic rhinitis and 81 were totally asymptomatic. All patients underwent measurement of nasal specific IgE using a validated technique (nasal IgE test). RESULTS A family history of atopy was significantly more frequent in symptomatic patients than in asymptomatic patients (P<.0001). The result of the nasal IgE test was positive in 77.5% of symptomatic patients and in only 13.6% of asymptomatic patients (P<.0001). With regard to individual allergens, there was no association between clinical symptoms and a positive response to SPT, although there was a strong association between symptoms and individual allergens tested for nasal IgE. In symptomatic patients, there was only a slight correlation between SPT and nasal tests with allergens. CONCLUSION These findings suggest that the absence of specific IgE in the nasal mucosa may explain the absence of symptoms in most sensitized subjects and pave the way for further study of the behavior of mucosal IgE in asymptomatic and symptomatic subjects.