Asthma and Allergy Protection Possible From Early Allergen Exposure


A recent study done by scientists at the Johns Hopkins Children’s Center has shown that babies who are exposed early to allergens could be protected from allergies and asthma later in life. Allergens include pollen, household bacteria, pet dander and even cockroach droppings.

The study was announced on June 6 in a news release from Johns Hopkins, and was published in the Journal of Allergy and Clinical Immunology the same day. It supports the long-held belief that children exposed to germs on farms were less likely to be sensitive to allergens. Earlier studies have suggested the same findings, and now inner-city children can be added to the group of those potentially protected from allergies and asthma.

Inner-city children may have an increased asthma risk, as they are likely to be exposed to pollutants as well as high levels of mouse and cockroach droppings. However, if children from such areas were exposed to allergens before turning a year old, they would be more likely to benefit from them instead, as confirmed in the study from Johns Hopkins.

Early exposure to certain allergens and bacteria, along with antibodies in breast milk and possible genetic factors, add to the protection of a child’s immune system and may prevent asthma and allergies. The onset of wheezing, a common symptom of asthma, is decreased as well.

Dr. Robert Wood, the study’s author, who specializes in allergy and immunology, said when initial allergen exposure occurs, it “may be critical.” He added that certain allergy triggers could be vital in shaping one’s immune system, especially when exposure to them occurred within the first year of life.

The study examined 467 inner-city newborns from New York, St. Louis, Boston and Baltimore. Investigators were sent out to each child’s home to assess the types and levels of allergens present, and tested the infants for allergies and wheezing. Dust samples were analyzed to determine how much and what types of bacteria were present.

The results showed that babies exposed to animal dander and cockroach and mouse droppings before turning a year old were less likely to develop wheezing at three years old. Compared to babies who were exposed to allergens, babies who were raised in relatively cleaner homes were subject to allergies and possible wheezing later. Also, the more exposure to different types of allergens and bacteria a baby had, the more protected the child’s immune system was from allergy triggers.

The study supports the “hygiene hypothesis,” which links the increase in allergy reports to many children having grown up in cleaner environments. The advent of hand sanitizers has also been named as a cause for the rise in allergy sufferers. With the body not having to fight off germs in one’s surroundings, allergies to dust and other triggers are likely to develop.

The CDC reports that one in 11 children in the U.S. have asthma – that is seven million children. Black children are twice as likely to have the condition compared to their white peers. According to 2003 statistics from the Asthma and Allergy Foundation of America, one in five Americans suffer from asthma and allergies with indoor and outdoor allergens being the most common triggers.

In addition, there have been reports stating that this year’s allergy season has been made worse thanks to the preceding harsh winter. The drought in California is also seen as being partially responsible for this longer season of triggers. Babies and children are more vulnerable to allergens due to environmental stimulants. Early exposure to allergens may possibly help protect children from allergy and asthma related symptoms.

By Sibylla Chipaziwa

USA Today
Johns Hopkins Children’s Center
Asthma and Allergy Foundation of America
Petaluma 360
Northern Virginia Daily