weigh in. Be weighed; also, be of a particular weight. For example, Because it was such a small plane, the passengers and their luggage had to weigh in before takeoff , or The fish weighed in at 18 pounds. [Late 1800s] See also: weigh.
Asthma and allergic diseases, such as allergic rhinitis (hay fever), food allergy, and atopic dermatitis (eczema), are common for all age groups in the United States.
Rhinitis Overview. There are two types of rhinitis: allergic and non-allergic. Allergic Rhinitis. If you have allergic rhinitis, your immune system mistakenly identifies a typically harmless substance as an intruder. This substance is called an allergen.