For some, coping with asthma is a daily part of life. This condition can be aggravated by seasonal allergies, increasing possible triggers. What are the connections between allergens and asthma development?
And can typical treatments like allergy shots help those who suffer from these types of allergies?
Asthma, according to PubMed Health from the US National Library of Medicine, causes difficulty breathing due to swelling and narrowing of the lung airways. Symptoms like coughing, shortness of breath, wheezing and tightness in the chest are common.
During an asthma attack, the muscles around the airways of the lung tighten and air passage lining swells, limiting the amount of air that is able to pass through.
For some, asthma attacks can be caused by exposure to allergens. Things like dust, pet fur, pollen and mold are common triggers, as are other factors like colds or exercise.
Asthma becomes an emergency when certain symptoms come into play, including drowsiness, a bluish tone in the face, or severe anxiety in response to difficulty breathing.
Allergen Exposure at a Young Age
A recent study, published in the August 2012 issue of the Journal of Allergy and Clinical Immunology and led by Tiina Reponen, PhD, examined how allergens exposed to infants may affect the development of asthma later in life.
The study followed 289 children of at least one parent with allergies from the age of eight months to seven years. At the outset of the study, dust samples were collected and the infants’ homes were analyzed for 36 molds.
At the end of the study, researchers evaluated the then 7-year-olds for asthma, based on lung function tests and reported symptoms, as well as testing their response to allergen skin pricks. A wide range of factors like cigarette smoke exposure, family history of asthma, age of home and visible mold at the one year old mark were also considered.
Asthma was found in 24 percent of the children at the end of the study. The presence of three mold spieces (Aspergillus ochraceus, Aspergillus unguis, and Penicillium variabile) were commonly found in the homes of the asthmatic children as infants, indicating a possible connection.
These three types of mold are commonly found in water-damaged buildings.
According to Reponen, “"This is strong evidence that indoor mold contributed to asthma development and this stresses the urgent need for remediating water damage in homes, particularly in lower income, urban areas where this is a common issue. Therapeutics for asthma may be more efficient if targeted toward specific mold species.”
Because these children were considered high-risk for asthma and allergies (due to their parents also having allergy problems), research needs to be extended to determine if the same risks apply to children not born into allergic families.
Though larger scale research needs to be completed, this study does warn parents of a potential risk and highlight the importance of keeping a home dry and clear of mold.
The Merits of Allergy Shots
For people with allergy-related issues of all types, allergy shots are a common treatment option. Allergy shots expose patients to a small but increasing amount of an allergen, slowly building up their immunity to the trigger over time.
However, the merit of allergy shots to asthmatic patients, like the children in the previous study who might have developed asthma partially in response to mold exposure, has been long debated.
One study, published in the Journal of Allergy and Clinical Immunology in 2002, closely explored the subject and provided some insight.
This study, led by Christian Möller, MD, PhD, followed 205 children aged six to 14 for three years. The patients were recruited from six pediatric allergy centers in different European countries and had allergies to birch, pollen or both.
At the beginning of the study, 20 percent of the children reported mild asthma symptoms during pollen season.
According to the authors, the goal of the study was to determine whether immunotherapy (i.e., allergy shots) with specific allergens could reduce the risk of asthma development.
The subjects were divided into a group who received allergy shots and a group who did not. Both were allowed to continue using normal medication to treat their allergy symptoms as needed.
After 3 years of treatment with allergy shots or with medicine alone, the children were measured for asthma symptoms and the results compared. Of the children who did not have asthma symptoms before the start of the study (151 kids in total), 24 percent who received allergy shots developed the disorder (19 out of 79 kids). In comparison, 44 percent of the children in the group who did not receive allergy shots developed asthma (32 out of 72 kids).
In this study, a three-year immunotherapy treatment did seem to prove effective in preventing the development of asthma in some children with allergies.
It is no doubt the debate will continue as research continues to move forward. Patients with allergy-aggravated asthma should speak to their doctor about what treatment regimen is best for them.
Parents of children with these conditions should also take care to ensure that friends, family and teachers are aware of the condition and how to help. Making sure that caregivers know when symptoms cross the line from uncomfortable to dangerous can be crucial in the health of the patient.