- © 2007 Canadian Medical Association or its licensors
Doctors should unite to lobby governments to ensure that the increasing numbers of asthma and allergy sufferers have access to necessary medications, says Dr. Susan Waserman, past-president of the Canadian Society of Allergy and Clinical Immunologists.
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Nearly 12% of Canadian children aged 12–19 have asthma — 4 times the rate 2 decades ago. Photo by: Canapress
Children with asthma have poorer health outcomes and quality of life when their families face financial hardships paying for prescription medication, either because of high copayments or lack of drug coverage, according to research presented at the 2nd annual AllerGen conference held in Hamilton, Feb. 11 to 13.
The conference addressed myriad issues including the cost of medication, the role of the environment, the rising incidence of food allergies and the genetic basis of asthma.
Multiple expensive medications are routinely prescribed for asthma, the most common chronic disease of childhood in developed countries. In Canada, almost 12% of children aged 12–19 have asthma, 4 times the rate 2 decades ago. Food allergies have also risen dramatically during the same period, said Dr. Judah Denberg, scientific director of AllerGen, the Allergy, Genes and Environment Network Centre of Excellence, which was launched in 2005 and now includes 150 researchers.
Patients can't do without inhalers and epi-pens, but these medications can be quite expensive, notes Waserman, who is on an advisory committee for AllerGen. Epi-pens for allergic reactions cost about $120, while controller drugs for asthma cost about $60 to $70 for a month's supply.
Financially pressed parents often skip buying the more expensive controller medication and instead rely on less pricey symptom relievers for asthma, which should not be used regularly, said Wendy Unger, a scientist at the Hospital for Sick Children in Toronto.
New Ontario research shows that 21% of children and 24.6% of adults who end up at emergency wards because of asthma attacks have no drug plans, despite the fact that only about 10% of Canadians have no drug coverage (Chest 2006;129:909-17).
In reviewing the widely varying rates of public drug plan coverage for children across Canada, Ungar noted that provinces don't agree on “the importance of providing comprehensive coverage for all children” and little attention has been paid to this vulnerable population. Ungar recommends that doctors consult with their patients about asthma drug costs before writing prescriptions.
Asthma symptoms can also be dramatically reduced when attention is paid to the home environment, according to a study by Dr. Tim Takero of Simon Fraser University. The study evaluated home interventions including providing special mattress covers and reducing the impact of mould, pets, roaches, tobacco smoke, mites and moisture (Am J Public Health 2005;95:652-9). “Housing is an important determinant of respiratory health… and improvements could have a major impact on asthma,” said Takero, who recommended that government departments of health and housing be merged.
Outdoor air also has a clear impact. A California children's health study found a reduction in lung function in children living closest to highways, and several European studies have linked traffic with asthma, Dr. Jeff Brook of Environment Canada reported.
Anaphyalxis is also on the rise, though to date it has received less research attention than asthma. A Montréal public school study revealed, through testing, that 1.5% of children were allergic to peanuts, Waserman noted (J Allergy Clin Immunol 2003;112:1223-8). Meanwhile, a McGill University study found an annual incidence rate of 11.1 for accidental exposure to peanuts in a group of children with mild to severe peanut allergies (J Allergy Clin Immunol 2006;118:466-72).
Waserman stressed the need for people with food allergies to be seen by specialists because misdiagnosis and misinformation can affect a patient's quality of life. But for nonurgent cases, wait times for specialists can stretch over many months since only 129 allergy and immune disease specialists were practising in Canada in 2004 (1 for every 247 863 Canadians).
In other research, about 120 “susceptibility” genes have been associated with asthma, and 5 main candidate genes have been identified, AllerGen attendees learned. Asthma is a “really complex disease” and it is challenging to identify what genes and other processes are associated with it, said Yohan Bossé, a researcher at McGill University and the Genome Québec Innovation Centre. Bossé has found that mice bred without the vitamin D receptor fail to develop experimental allergic asthma.
Researchers are particularly keen to study the gene and environment interaction, which will likely provide some explanation for the rising rates of asthma and allergies; however, researchers acknowledge they need to know much more about both sides of the equation.