Is chocolate a food allergen?

Many people believe they are allergic to chocolate. However, a true chocolate allergy, being allergic to cocoa, is  very rare. Many reactions to chocolate are caused by an intolerance or allergy to one or more of the other ingredients or food additives in chocolate. These include soy lecithin, milk, corn syrup, gluten, nuts, flavorings, and dyes.
 
A chocolate's quality helps determine the number and amount of allergenic additives. Mass–produced chocolate generally contains less cocoa butter and more milk, soy lecithin, gluten, and flavorings. If you have food allergies, be sure to check the label before consuming chocolate.
 
Source(s):
Yourtotalhealth.com "Chocolate Allergies"