What is an allergen? Posted on December 31, 2018March 8, 2023 by 0 Vote Up Vote Down Ask A Doctor Staff asked 4 years ago What is an allergen? 1 Answers 0 Vote Up Vote Down Ask A Doctor Staff answered 4 years ago Allergens are organic particles, which attach to the nasal mucosa or respiratory mucosa and lead to the development of an antibody, which creates a series of chemical reactions leading to allergic symptoms. Please login or Register to submit your answer Username or Email Address Password Remember Me