For those with true allergy to a food, taking an antihistamine during an allergic reaction may be helpful to relieve the hives and itching. They have little role in relieving any type of respiratory problem. If a child is having anaphylaxis or respiratory symptoms (e.g. throat closing, coughing, wheezing), the only treatment that is effective is injectable epinephrine (EpiPen or AuviQ). For adverse reactions to foods, which are not allergic in nature, antihistamines have little effectiveness.