An epidemic of allergic disease
The incidence of allergic disease such as asthma, rhinitis, atopic dermatitis and food allergies has increased to epidemic proportions in both the developed and developing worlds. Currently 40% of the US population is allergic to one or more common inhaled or food allergens, and half of those are symptomatic at any one time. With a nearly four-fold increase in allergic disease between 1979 and 1992, there are now over 60 million individuals with allergy and asthma in the US, over four times the number of people with diabetes.
Asthma affects 5-6% of the US population, or an estimated 20 million persons, including 6 million children. Recent trends suggest an increase in both the prevalence and morbidity of the disease, especially in children younger than 6 years.
The cost to society due to the morbidity and mortality of the disease is far greater, centered principally on the 2-3 million asthmatics in the US who are not well-controlled with available prescription inhaled bronchodilators and corticosteroids. Lost work and school time from asthma is estimated at approximately 100 million days of restricted activity, including more than 14 million total missed days of school, each year. More than 2 million emergency department visits and 10 million outpatient visits occur annually. According to a recent CDC National Asthma Control Program Report, there are an estimated 500,000 hospitalizations and 5,000 deaths annually, representing a total cost to the nation of $56 billion. While the death rate from asthma has dropped over the past 10 years, African Americans remain 2 to 3 times more likely to die from asthma than any other racial or ethnic group.
Effective treatments for severe food allergy represent major unmet needs both in the US and throughout the world. It has become clear that that anaphylactic allergy to foods is far more common than was appreciated only a decade ago, reaching epidemic proportions. According to the Center for Disease Control (CDC) in 2007, food allergy affects up to 2.5% of the overall US population and 4% (3 million) of children under age 18. Peanut, tree nut, egg and milk allergies are the most prominent, especially in children, while allergies to crustaceans (shellfish) and fish along with peanut and tree nuts are more important among adults.
Peanut allergy alone affects 1% of the US adult population, 1.8% of 4-5 year olds and is among the most severe food allergies, resulting in 200,000 emergency room visits, over 10,000 hospital admissions and over 200 deaths per year, far more than the other prominent IgE mediated food allergies. In contrast to some other major food allergies, such as to milk and eggs, peanut allergy generally does not disappear with age. Each year 14% of school aged children accidentally ingest a food to which they are allergic. In food-allergic individuals, strict avoidance of exposure is the only means of prevention, and the only available treatment for anaphylaxis when accidental ingestions occur is rapid administration of injectable epinephrine.