Studies presented at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting 2017 in Boston, Massachusetts, and published this week examine the links between early exposures and response from the immune system later in life.
Children born in a house where a mother lived with a dog during pregnancy may gain early protection against eczema, according to a study presented last week at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting 2017 in Boston, Massachusetts.
The study highlighted a progression that lead author Gagandeep Cheema, MD, said most parents fail to understand. “Although eczema is commonly found in infants, many people don't know there is a progression from eczema to food allergies to nasal allergies and asthma," said Cheema, of Henry Ford Health Center in Detroit, Michigan, in a statement. "We wanted to know if there was a protective effect in having a dog that slowed down that progress."
Nearly 800 pairs of mothers and children enrolled in the Wayne County Health Environment and Allergy Longitudinal Study, with mothers interviewed during pregnancy and the children seen at follow-up visits at ages 2 and 10. A dog was considered living in the home if the mother reported keeping it inside at least an hour a day.
Children who lived with a dog were found to have a significantly lower risk of eczema at age 2, although the benefit waned by age 10.
A second study examined the effects of having a dog on childhood asthma. This study found that children who spend time with a dog can be affected in 1 of 2 ways: if children are not affected by an allergen the dog carries, being around the pet offers a protective effect against asthma symptoms. But for children affected by the allergen, the dog’s presence may cause more asthma symptoms.
The studies add to the puzzle for researchers trying to connect the effects of early exposures to later inflammation and immune response. A review article published Monday examined available literature on the question of whether too many antibiotics contribute to allergies later in life.
Published in the European journal Allergy, the article found that early exposure to antibiotics was associated with an increased risk of hay fever, eczema, and food allergies later in life.1 However, there was no association between early antibiotic exposure and certain biological measures, such as positive skin prick tests or elevated allergen-specific serum/plasma immunoglobulin E levels, which are antibodies that cause allergic reactions.