Early upper respiratory infections linked to ragweed allergy, asthma

A high number of upper respiratory infections during an infant’s first year increases the risk for early ragweed sensitization and asthma at age 7 years, according to research presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

To determine the association between first-year upper respiratory infections (URIs) and subsequent ragweed sensitization and asthma, the researchers assessed data from the Cincinnati Childhood and Allergy and Air Pollution Study prospective cohort. Included in the CCAAPS were high-risk births of one or more confirmed allergic parents.

“A high number of respiratory infections early in life is associated with early sensitization to some aeroallergens,” Leilanie Perez Ramirez, MD, MS, of the Cincinnati Children’s Hospital, in Ohio, who presented the data, told Healio Family Medicine. “A high number of respiratory infections (including upper and lower) is associated with early sensitization to ragweed, sensitization to mold at age 3 and asthma at age 7. When combined, having a high number of respiratory infections and early sensitization to mold confers an increased risk for asthma at age 7 compared to either individual risk factor alone.”

The researchers defined arly sensitization as at least one positive skin prick test from ages 1 to 3 years, and late sensitization as negative skin prick tests during 1 to 3 years, but positive at 7 years. Regarding URIs, high frequency was defined as more than six infections by 1 year.

According to the researchers, among the 710 children included in the study, 59% had early sensitization and 10% had late sensitization. In addition, 96% of the children had more than six URIs during their first year. The researchers found that a high number of URIs was significantly associated with a nearly twofold increased risk for developing an early allergy to ragweed, after adjusting for pets, breastfeeding, day care and antibiotic use (aOR 1.8; 95% CI, 1.01-3.1, P = .046). In addition, early aeroallergen sensitization (aOR 2.7; 95% CI, 1.5-4.7, P = .001) and a high number of URIs (aOR 2.33; CI 95%, 1.4-3.9, P = .002) were associated with developing asthma at 7 years. The researchers found no association between a high number of URIs during the first year and late sensitization to any aeroallergen.

Disclosure: Perez Ramirez reported no relevant financial disclosures.

Reference:

Perez Ramirez L, et al. Paper 292. Presented at: American Academy of Allergy, Asthma & Immunology Annual Meeting; March 4-7, 2016; Los Angeles.