Cinnamon, garlic, cumin, cardamom, and other spices can liven up all kinds of dull dishes. But for some people, these can also set off an allergic reaction. Spices are also commonly used in cosmetics, and since specific spices may not always appear on product labels, they can be hard to avoid. Cinnamon and garlic are two of the more common triggers of allergic reactions. But in general, the hotter the spice, the stronger the reaction.