Latex—a natural rubber made from the sap of the Hevea brasiliensis tree—is used to manufacture many items, including bicycle and wheelchair tires, toys, some balloons, examining gloves, household gloves, surgical tubing, rubber bands and condoms. The major exposure of concern is to the powder from latex gloves, because the latex proteins adhere to the powder and become airborne when these gloves are put on, taken off or snapped.
A person allergic to latex is actually allergic to one or more proteins (allergens) found in the sap from the rubber tree. Interestingly, these proteins—or ones very similar—can be found in banana, kiwi, avocado, potato, strawberries, peaches and chestnuts. Both latex and these foods are plant-derived, and contain chitinase I, a pan allergen responsible for the latex-fruit syndrome. Therefore, people who are allergic to latex may have cross-reactions to these foods. Interestingly, the chitinase I allergen is destroyed by heating, so many people can eat the cooked food but not the raw form.
In addition, raw latex is mixed with a variety of different chemicals that allow the latex proteins to polymerize, or take shape, into long chains that can then be manipulated to form solid objects. Some of these chemicals can cause contact dermatitis, an allergic skin reaction that appears as mild to severe itchy, red bumps or rashes on the skin directly exposed to the rubber product, typically the hands. However, these chemicals do not cause specific IgE type symptoms such as asthma, hives, or hayfever.