The skin of a mango is safe to eat as long as the person eating it does not have a strong sensitivity to urushiol, the active chemical found in poison ivy, poison sumac and poison oak, About.com states. Handling or consuming the skin can cause dermatitis in allergic individuals.
Most people avoid the skin of the mango fruit because it's tough and bitter tasting, writes Anne Marie Helmenstine, Ph.D. on About.com. The skin is actually full of beneficial antioxidants, such as mangiferin, norathyriol and resveratrol. Urushiol is also present in the flesh of the fruit but in much smaller qualities than the skin. For those who prefer to avoid the skin, it's easy to peel a mango with a common vegetable peeler or paring knife.