As of Thursday, May 23, 2013
DEAR DOCTOR K: I’m a nurse who is allergic to latex, so I always use latex-free gloves. But I still occasionally break out in hives. Why?
DEAR READER: A product may claim to be “latex-free” or state that it “does not contain latex.” But the truth is that no existing tests can show that a product is completely free from latex.
“Natural rubber latex” comes from the sap of the rubber tree. This material is used to make a host of stretchy products, including adhesive bandages, condoms, gloves used in health care and dishwashing, balloons, rubber bands, baby bottle nipples and more.
Natural rubber latex can cause an allergic reaction because it contains proteins that set off some people’s immune systems. A latex allergy usually occurs in people with repeated exposure to natural rubber latex. That’s why they’re more common in health care workers and frequent surgical patients.
Hives or welts are a common allergic reaction to latex exposure. So are swelling, a runny nose and sneezing; red, itchy or teary eyes; headache, sore throat, abdominal cramps; or chest tightness, wheezing or shortness of breath. Sometimes the reaction can cause anaphylactic shock, which can be deadly.
Not everyone who is latex-sensitive has hives or welts. Some people get contact dermatitis, consisting of a skin rash and itching that start one to several days after contact with a latex product. Over time and repeated exposure, contact dermatitis can cause dry, crusted scabs on the skin.
The big mystery with latex allergy — and most allergies, for that matter — is why it exists. It is our immune system that causes allergies. The immune system is supposed to protect us from dangerous foreign substances and microbes. But latex isn’t dangerous to us — nor are many other things to which people have allergies, such as pollen, house dust or cat dander. Yet the immune system (or, at least, one part of it) overreacts and goes to war. In trying to protect us, it makes us sick.
Synthetic latex is an alternative to natural latex. It doesn’t provoke allergies. You can (and should) use gloves made from synthetic latex. But even that’s not a guarantee, because products made without natural latex can be contaminated with latex proteins during the manufacturing or packaging process.
Since latex is found in so many products, the best you can do is make smart choices based on information on product labels. Use gloves made from synthetic latex and avoid those made with natural rubber latex. When you find a product that doesn’t provoke an allergic reaction, stick with it.
Dr. Anthony Komaroff is a physician and professor at Harvard Medical School.
Send questions to Anthony L. Komaroff, M.D. through his website: www.AskDoctorK.com. You also can mail him in care of Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.