By Bruce A. Berlow

Sansun Highlights 1997

During the past decade, a strange and troubling new epidemic has taken place on a global scale: allergic reactions to latex or rubber products. Not only has this epidemic ruined careers, it has been responsible for a number of deaths.

To understand this epidemic, it is important to know how rubber is made. First of all, latex is not synthesized in a laboratory - it is a completely natural product obtained from the Brazilian rubber tree, Hevea brasiliensis. Latex is harvested much like maple syrup, from slits made in the tree's bark. The milky sap is pooled, treated with preservatives, then centrifuged to concentrate the rubber solids. Various chemicals are then added and the latex emulsion is used to make products ranging from tires to rubber gloves.

The puzzling thing about latex allergy is that it is a new disease; it wasn't a problem until the late 1980s. Since then it has burgeoned into a major health problem. The most compelling clue to the cause of this new phenomenon was the adoption of "universal precautions" in 1987. This policy mandated use of latex gloves to prevent transmission of bloodborne infections such as AIDS and hepatitis. As a result, the use of latex gloves skyrocketed; nearly nine billion gloves will be sold in the U.S. this year (Figure 1). Two years after universal precautions were adopted, however, the Food and Drug Administration was besieged with reports of serious reactions to latex.

It also became clear that certain groups - nurses, doctors, surgeons, dentists, rubber industry workers, and patients who had undergone multiple operations - were at especially high risk of latex allergies. The common denominator appeared to be repeated exposure to rubber products. We now believe the cumulative exposure reached a critical mass for susceptible individuals to become sensitized to latex proteins. Nearly 10 percent of healthcare workers are now allergic to latex, and certain groups such as children with spina bifida are at even higher risk. Over half of these children will develop latex allergies, so it is recommended they avoid latex exposure from birth.

One other group is at increased risk: individuals with other allergies such as hay fever, asthma, and food or drug allergies, who have a tendency to make allergic responses. Their risk is similar to that of health care workers.

Reactions to latex can take a variety of forms. There are three types of skin reaction: irritant ("dish-pan hands"), delayed hypersensitivity (like poison oak, usually caused by chemical additives) and urticaria or hives. Other reactions can mimic hay fever or asthma. The most serious are systemic reactions: angioedema (swelling of the lips, tongue, or throat) and anaphylactic shock. There is one other unusual manifestation: food allergies. Individuals with latex allergies are more likely to react to certain foods, especially bananas, avocados, chestnuts and kiwi fruits.

The most important diagnostic test for latex allergies is the medical history. Seven questions (see insert) can help determine the likelihood of latex allergy. To confirm the diagnosis, the most commonly used tests are blood tests to identify antibodies to latex proteins. Skin tests are also sometimes helpful, but have the potential to provoke serious reactions. Finally "use" tests, involving incremental exposure to latex under carefully controlled conditions, can help clarify ambiguous cases.

Treatment requires avoidance of latex-containing medical and consumer items. Many hospitals now offer latex-free wards and operating rooms for allergic patients. It is also advisable to wear a MedicAlert bracelet (1-800-432-5378), carry a prefilled epinephrine autoinjector in case of an acute reaction, and keep a supply of non-latex gloves for visits to healthcare providers. All providers, including dentists, should be notified of a patient's latex allergy.

It is important to remember three key facts: 1) the severity of a previous reaction does not reliably predict the severity of a future reaction, 2) even casual contact with latex can cause severe reactions in highly-sensitive individuals and 3) latex allergy can be mistaken for other allergies. The good news is that with proper recognition, diagnosis, and management, most latex allergy sufferers can avoid the complications of this newest healthcare epidemic.

Could You Be Allergic to Latex?

Have you ever had:

1. Any adverse reaction to rubber gloves, glove powder, balloons or other rubber products?

2. Severe reaction during surgery, urinary catheterization, barium enema or other medical procedure?

3. Red, itchy eyes; nasal congestion or sneezing; cough or wheezing in a medical or dental setting?

4. Genital itching or swelling with vaginal/ rectal exams, condoms, or diaphragms?

5. Itching or swelling of the lips with balloons or after dental exams?

6. Rash or itching upon contact with rubber toys, sporting goods or latex apparel?

7. Itchy mouth or other adverse reaction to bananas, avocados, chestnuts or kiwi fruits?

Bruce A. Berlow, M.D. received his medical degree from the University of North Carolina, Chapel Hill. He completed his residency at the University of California, San Diego, where he performed his Fellowship in Adult and Pediatric Allergy and Immunology and Pediatric Pulmonary Medicine. Prior to joining Sansum Medical Clinic in 1980, he was a clinical instructor at the University of California School of Medicine, Department of Pediatrics. A Fellow of the American Academy of Allergy, Asthma and Immunology, Dr. Berlow's special interests include asthma, allergic rhinitis, urticaria, immunodeficiency, food allergy and drug allergy.