Which of the following is an allergen?
Milk
Seafood
Dust
An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Allergens can be found in a variety of sources, such as dust, mites, pollen, pet dander or even royal jelly. Food allergies are not as common as food sensitivity, but some foods such as peanuts (a legume), nuts, seafood, and shellfish are the causes of serious allergies in many people.