Allergies are complicated, especially food-borne allergies. Sometimes the reactions are simple, a rash or eczema that can be easily treated with an antihistamine like Benadryl, or a hydrocortisone cream. But others are severe, and there is nothing more terrifying to a parent than seeing their child have an allergic reaction. As little as a single drop of milk can cause a person to go into anaphylactic shock if they have a severe milk allergy.; "Because lactose intolerance is so common, people don't think of milk allergy as something that can be significant or severe," said Ruchi Gupta, MD, director of the Center for Food Allergy and Asthma Research at the Northwestern University Feinberg School of Medicine in Chicago, as reported by WebMD.