It's a shame that some people just can't tolerate the world's number one comfort food. This allergy is rare, and the root of the problem typically lies with milk and nut ingredients within chocolate. Allergies can also be trigged by chocolate's cocoa bean.
In rare cases, people with allergies and asthma are affected by the small trace amounts of insect parts that contaminate foods growing close to the ground. Each chocolate bar contains an average of eight insect parts, which is generally safe according to the FDA. Some side effects of an allergy to bug parts in foods include migraines, cramps, itching or hives.