Latex Allergy

Erin M. Warshaw, MD

In This Article

Natural Rubber Latex and Delayed-Type Hypersensitivity

Natural rubber latex refers to products made from latex, which is the milky sap of the Hevea brasiliensis tree. To stabilize the elastic properties of latex and to create a commercially acceptable product, many chemicals are added to the latex sap during the manufacturing process, including accelerators, antidegradants, emulsifiers, stabilizers, extenders, colorants, retarders, stiffeners, biocides, and ultraviolet light absorbers. Allergy may develop to plant proteins in the latex sap itself, or to chemical additives mixed with the latex sap to make commercial rubber products.

There are two types of allergic reactions to rubber products: type IV (delayed-type hypersensitivity) and type I (immediate-type hypersensitivity) ( Table I ). Type IV is a cell-mediated reaction. The most common type of reaction to rubber is delayed-type hypersensitivity to chemicals added to latex during manufacturing, not to latex itself. Rubber accelerators (mercaptobenzothiazoles, carbamates, and thiurams) cause the majority of these reactions,[6] and screening panels for these accelerators are found on most basic patch test trays. There have been a few reported cases of delayed-type allergy to raw latex without added chemicals, many with concomitant immediate-type allergy as well.[7,8] Delayed-type reactions typically result in a pruritic eczematous dermatitis hours to days following contact with the allergen.