While allergic reactions to ingesting coconut are rare, it's not uncommon to have an allergic reaction to touching them. You'd think that it would be harder for your body to deal with things you put in your mouth than stuff that just touches your skin, but coconuts are an exception. What's more, they show up in all kinds of skin care products, both for their delicious scent and their ability to moisturize and soften skin.
However, coconuts can also be made into coconut diethanolamide, a detergent that helps create a stable lather when you're washing with soap. Like sodium lauryl sulfate (SLS), coconut diethanolamide can break down skin's oily barrier layer and dry it out, but certain people develop more intense allergic reactions to it. Since coconut diethanolamide is a common ingredient in skin care products such as barrier creams and hand protection foams, sensitizing can happen rapidly. You may begin to develop reactions after using a product for two or three months. Regular rinse-off soaps, however, take much longer to produce a reaction -- more like five to seven years [source: Duffill]. Check ingredient lists for coconut diethanolamide, and be aware that it may be masquerading under such names as coconut oil acid, cocamide DEA, ninol, witcamide and calamide.