The beetle’s back and the crab’s shell owe their toughness to a common compound called chitin that now appears to trigger airway inflammation and possibly asthma, UCSF scientists have found.Insects, molds and parasitic worms - all common sources of allergies or inflammation — produce billions of tons of chitin a year. Humans and other mammals lack chitin, but we do have specialized enzymes to break it down. The scientists wondered why. [click link for full article]