It's estimated that 5.72 million people in the U.S. are allergic to fragrance. If you're one of them, you may think buying a product labeled unscented or fragrance-free puts you in the clear. Not necessarily. According to the FDA, these terms have no legal definition and mean nothing more than that a product has no perceptible odor. A better bet: Have your dermatologist do a patch test to see which chemicals affect you. Then scour ingredient lists to avoid them. If a label simply says "fragrance," call the manufacturer for a detailed listing. Or apply a small amount to the bend of your arm twice daily for a week to make sure the product won't harm your skin before you rub it all over.