Allergens enter the body in one of three ways. Medicines that can cause allergic reactions are injected or ingested. More than half of all allergy sufferers fails to recognize their symptoms at first, falsely believing they have a cold or the flu. Prevalence An estimated 50 to 60 million Americans. About one of every five adults and children suffer from allergies, including allergic asthma.
Allergies are the sixth leading cause of chronic disease in the United States.
Allergies have a genetic component. If only one parent has allergies, chances are one in three that each child will have an allergy. More than 33 million Americans suffer from chronic sinusitis. Allergies are the most frequently reported chronic condition in children, limiting activities for more than 40 percent of them. An estimated 6 to 10 million Americans are allergic to cats.