One of the most common types of allergies is allergic rhinitis, or hay fever, which results from allergens in the air. As of 2017, an estimated 7.7 percent of adults in the U.S. had been told by a doctor they had hay fever in the past year, while around 10.8 percent of those aged 12 to 17 years were told they had such an allergy. As hay fever is caused by allergens in the air, geographic differences occur in prevalence rates, with the West reporting higher instances than other regions.
Skin allergies can be caused by things such as metals, some medications, latex, soap, laundry detergent and fabric softeners and affect around 13.5 percent of all children under the age of 18 years. Allergic reactions to food and medications can also cause skin symptoms such as itching, redness, and bumps. A recent survey from Statista found that around 25 percent of adults in the U.S. had drug intolerances. Among the drugs most commonly associated with allergies were penicillin or antibiotics and aspirin.
Allergies are often associated with asthma as the same substances can trigger both allergies and asthma. There is even a type of asthma known as allergic asthma that is triggered by an allergy, for example pollen or mold. In 2018, around 7.9 percent of the U.S. population currently had asthma with rates highest among those aged 5 to 14 years.
Given the high number of people who suffer from allergies, it is unsurprising that the market for allergy medication and relief products is sizable. In 2018, an estimated 40.35 percent of people aged 30-49 years in the U.S. bought medications because of allergies. In 2016, Allegra, one of the leading OTC brands for cough, cold, allergy and sinus problems, earned over 220 million dollars in revenue.