The Crazy Quiz Question today was: More people are allergic to this food than any other food?  The Answer is

How common is cow's milk protein allergy?

Cow's milk allergy is the most common food allergy in young children. Fortunately, most babies outgrow milk allergies by their second or third year. In the meantime, parents of babies with milk allergies can be reassured that - although there is no treatment that can cure milk allergies - symptoms can be controlled through a dairy-free diet.

(via Cow's Milk Protein Allergy.)