Asthma and allergic diseases often coexist, with an estimated 80% of asthma patients also suffering from allergic rhinitis. Both conditions share common characteristics, and allergic rhinitis is a risk factor for the development and severity of asthma. Despite the widespread use of allergen skin testing to evaluate allergic diseases, data describing skin reactivity patterns in U.S. asthma patients have been lacking—until now.
“This report presents one of the most comprehensive evaluations of skin test reactivity among asthmatics in relation to a wide variety of factors,” said Rohit Katial, MD, an allergist and immunologist at National Jewish Health and senior author of the paper. “By looking at all permutations and levels of asthma severity, these findings underscore that a significant majority of asthma patients also manifest allergic rhinitis.”
Researchers conducted a chart review of 500 randomly selected adult and pediatric patients from the National Jewish Health electronic health record. They evaluated data based on immunoglobulin E (IgE) levels, the age of asthma onset, asthma severity (indicated by corticosteroid use), sex, and race. Allergen reactivity data were collected for 10 allergens, including perennial allergens (cockroach, animal dander, dust mites, and others) and seasonal allergens (trees, grasses, and weeds).
The study found that 75% of the subjects tested positive for at least one of the 10 allergens. Specifically, 68% tested positive for one of the seven perennial allergens, 60% for one of the three seasonal allergens, and 52% for both. Men showed higher reactivity than women for any sensitization and for perennial allergens, but no significant difference was observed in seasonal sensitization between sexes.
Skin test reactivity did not significantly differ based on the presence of a rhinitis diagnosis, indicating that rhinitis is not a sole predictor of an underlying allergic condition. The data also confirmed that patients with early-onset asthma tend to be more allergic than those with late-onset asthma. Perennial skin test reactivity was notably higher in early-onset asthma patients compared to late-onset patients, although this pattern did not hold for seasonal allergies.
“It was noteworthy that a previously held assumption that late-onset asthmatics tend to be non-allergic is incorrect,” Dr. Katial stated. “Almost two-thirds of the subjects in the late-onset group had skin test reactivity, suggesting that allergic disease should not be discounted even in late-onset asthma patients.”
This study highlights the prevalence and importance of allergic conditions in asthma patients, emphasizing the need for comprehensive allergy evaluations regardless of the age of asthma onset. The findings suggest that managing allergies could be crucial for effectively controlling asthma in many patients.
