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.
Antigens can be bacteria, viruses, or fungi that cause infection and disease. They can also be substances, called allergens, that bring on an allergic reaction. Common allergens include dust, pollen, animal dander, bee stings, or certain foods.