Rhinitis symptoms and IgE sensitization as risk factors for development of later allergic rhinitis in adults.
BACKGROUND
Rhinitis symptoms and IgE-sensitization often mismatch. Asymptomatic sensitization is an established risk factor for later rhinitis, whereas it is not clear whether rhinitis is a risk factor for later development of IgE-sensitization.


OBJECTIVE
To investigate whether nonallergic rhinitis is a risk factor for later development of IgE-sensitization in adults during an 8-year follow-up period, and whether asymptomatic sensitization is a risk factor for later development of rhinitis.


METHODS
In a population-based study of 15-69 years olds in 1990, 734 subjects were re-examined in 1998. On both occasions questionnaires on rhinitis symptoms were completed and serum IgE (against birch, grass, mugwort, cat, dog, and Dermatophagoides pteronyssinus) were determined (positive if >or=0.35 kUA/l). Asymptomatic sensitization: positive IgE levels without any rhinitis symptoms. Nonallergic rhinitis: rhinitis symptoms and no sensitization.


RESULTS
Asymptomatic sensitization to pollens, pets, or house dust mite was significantly associated with onset of rhinitis symptoms, also when changing baseline cut-off for sensitization to >or=0.1 or >or=0.7 kUA/l. The 8-year incidence of pollen-related rhinitis was 15.1% and 2.6% in subjects sensitized and nonsensitized to pollens, respectively (odds ratio 6.1, 95% CI 2.3-16.0). Persistent or intermittent nonallergic rhinitis was not significantly associated with later sensitization, yet a positive trend for development was observed in nonallergic pollen-related rhinitis.


CONCLUSIONS
Asymptomatic sensitization but not nonallergic rhinitis was a significant risk factor for later development of allergic rhinitis.
Bodtger
U
U
Allergy Clinic 7551, Copenhagen University Hospital, Copenhagen, Denmark.
Poulsen
L K
LK
Linneberg
A
A