Chocolate allergies are more commonly caused by sensitivity to another ingredient often found in chocolate. Some of the most common triggers of food allergies are common ingredients in chocolate products. They include:

• Cow’s milk (including components such as casein and whey). Milk is one of the common triggers of food allergies.
  
  
• Nuts. Nuts are one of the common triggers of food allergies and may cause a range of symptoms including anaphylaxis. Both peanuts and tree nuts are found in some chocolate bars. Chocolate may be made in a factory that also produces nut products and trace amounts of nuts can be present in the chocolate even if nuts are not listed in the ingredients. According to U.S. Food and Drug Administration (FDA) regulations, chocolate packages must indicate that the item was processed in a factory that also processes nuts.
  
  
• Wheat or gluten. Wheat and/or gluten are added to mass–produced chocolate–based products. These products are generally sold as “candies” and not as premium chocolate. Wheat is a common food allergen and gluten is a major source of food intolerance. According to FDA regulations foods containing these allergens must indicate their presence on food labels.
  
  
• Soybeans (including components such as soy lecithin). Soy is one of the common triggers of food allergies and intolerance and may cause a range of symptoms. Soy lecithin is an additive in many lower quality chocolates.
  
  
• Corn (including corn syrup). Corn is a common trigger of food allergies and corn syrup is commonly found in chocolate bars or other chocolate-containing products. FDA regulations require that foods containing corn indicate their presence on food labels.

In addition, people can have sensitivities to a particular food additive – substances added to foods that are not part of its basic raw ingredients. Additives are commonly used to achieve better preservation, taste, texture, nutrition or color. Additive sensitivities are less common than whole food allergies. Food additives that are commonly used in chocolate products include:

• Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Common preservatives that may be added to some chocolate products.
  
  
• Tartrazine. A yellow food coloring (also known as FD&C yellow number five) that may be added to some chocolate products.
  
  
• Nickel. Nickel is commonly found in chocolate, nuts, beer, tea, coffee and apricots. Nickel can cause contact dermatitis in sensitive people.
  
  
• Other additives. There are many other common chocolate additives including flavorings like mint, dyes for hard candy coating and other products that may cause reactions. FDA regulations do not require that flavorings, dyes or other additives are indicated on food labels.

There are also a number of chemicals commonly found in chocolate. Some of the commonly reported side effects of chocolate, like headaches, may be caused by a reaction to one or more of these chemicals and NOT due to an allergic reaction. Chemicals in chocolate that may cause reactions include:

• Caffeine. Caffeine can cause anxiety, sleep problems, difficulty concentrating, restlessness and heartburn. Withdrawal from caffeine may cause headaches and fatigue. Chocolate contains much less caffeine than coffee.
  
  
• Theobromine. An alkaloid with about one-tenth the stimulating effect of caffeine. Withdrawal from theobromine may cause headaches. Theobromine is toxic to dogs and other animals.
  
  
• Phenylethylamine. A chemical in the body that is similar to an amphetamine (a central nervous system stimulant). The amphetamine-like nature is responsible for mood swings and may cause blood vessels to dilate in the brain causing headaches in some people.
  
  
• Tyramine. This ingredient can trigger headaches in some individuals.