Changes in skin and nasal sensitivity to allergens and the course of rhinitis; a long-term follow-up study

Background: Allergic skin test reactivity tends to decrease with aging, but whether the decrease is associated with changes in symptom severity and duration of the disease or determined only by aging, is poorly understood. Objective: Our aim was to analyze skin test sensitivity some 20 years after primary testing and to relate possible changes in reactivity to aging, duration of rhinitis, and changes in severity of rhinitis symptoms. Methods: One hundred and seven rhinitis patients who had been investigated earlier were re-interviewed and their current allergy re-assessed after a follow-up of 23 years. All patients were skin prick tested with 22 to 26 common allergens. The allergic rhinitis status was verified with nasal allergen challenge. Results: Skin test reactivity showed a significant trend decreasing towards older age groups over the period between the two investigations. Rhinitis symptoms tended, on average, to become milder during the follow-up, but an association between skin test reactivity and changes in symptom severity could not be verified. Conclusions: Rhinitis symptoms tend to become milder and the allergic skin reactivity usually decreases in the long run, but these changes may occur independently of each other. In this study, the change in rhinitis symptom severity seems not to be related to the decrease in skin test reactivity.