Sensitization to common allergens
Serum samples were analyzed for total IgE and specific IgE antibodies
using the ImmunoCAP® system according to the
manufacturer’s guidelines (Phadia AB, Uppsala, Sweden). The tested
allergens were as reported elsewhere.13 In this study,
we focused on house dust mite (HDM) sensitization (positive = HDM-sIgE
>0.34 UA/ml).
Classification ofHDM-sensitized perennial AR
in young children
AR is IgE-mediated inflammation of the nasal mucosa. It is diagnosed
based on the presence of typical allergic symptoms and nasal
eosinophilia, and identification of the causative
allergen(s).18,19 AR in children, however, is often
undiagnosed, or misdiagnosed because of the multitude of causes for
rhinitis.18 Thus, we tentatively classified the
phenotypes of the nasal condition in young children in relation to
HDM-sensitized perennial AR based on 3 clinical criteria: persistent
nasal symptoms, nasal eosinophilia and HDM sensitization. The various
combinations of those 3 criteria make up 8 phenotypes, as shown in Table
1. We defined the subtype that was positive for all 3 criteria as
”classical AR”, and the subtypes that were positive for 2 of the 3
criteria as ”eosinophilic rhinitis”, ”AR without nasal eosinophilia” and
”subclinical AR”, respectively. We classified those 4 subtypes as
”AR-like phenotypes” (Table 1). Four subtypes that met only one, or
none, of the 3 criteria were classified as ”non-AR phenotypes” (Table
1).