Published Online: July 29, 2015
Allergic sensitization is a major risk factor for asthma and allergic rhinitis in children and young adults. Its impact on these conditions in later adulthood has been less studied. The prevalence of allergic sensitization has been shown to decline with increasing age. Therefore, other risk factors might gain importance among older subjects. Furthermore, specific airborne allergens might influence asthma and rhinitis differently.
In an article recently published in The Journal of Allergy and Clinical Immunology (JACI), Warm et al aimed to determine the influence of specific airborne allergens on asthma and allergic rhinitis in an adult population from Northern Sweden. Furthermore, the relation between the age of asthma onset and allergic sensitization was described. A randomly selected adult population in ages 21 to 86 years was examined with a structured interview during 2008 and 2009. Allergic sensitization was assessed by blood sampling measuring specific IgE antibodies to 9 common airborne allergens in the serum.
The authors found that older subjects with allergic rhinitis and/or asthma were less allergic compared to younger subjects. Further, the sensitization pattern for asthma and rhinitis differed. Participants who were sensitized to cat, dog, or horse allergens were significantly more likely to have asthma at the time point of the examination. Sensitization to any of these animals, but also to any pollen was strongly related to allergic rhinitis. The association between allergic sensitization and allergic rhinitis was strongest among adults younger than 41 years and weakened in the older age groups. A different pattern was seen for asthma, whereas sensitization to any of the animals was equally and strongly associated to asthma in all adult age groups. Participants who had developed asthma before school age were more often sensitized compared to participants with an asthma onset later in life.
The authors conclude that allergic rhinitis is strongly associated with sensitization to airborne allergens, but that this relationship weakens as patients grow older. This age-dependent relationship was not seen in subjects with asthma, and allergic sensitization, especially to animals, is important to consider also in older asthmatics. The finding of the strong association between an early age of asthma onset and allergic sensitization in adulthood suggests further longitudinal studies on the morbidity effect of persistent sensitization to airborne allergens in adult age.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.