The Latex Allergy Threat: Can We Keep Clinicians and Patients Safer?

And is there any such thing as 'latex-free'?

Jennifer Leavitt

April 26, 2017

When Australian mother and physician Pooja Newman descended into anaphylactic shock after a massive Adele concert balloon release, latex allergy got a great deal of media attention around the globe.^[1] But Dr Newman, who is also president of Anaphylaxis Australia, is not alone. The American Latex Allergy Association estimates that although a mere 1% of the general population is allergic to latex, some 8%-17% of healthcare workers have this allergy. (The Allergy & Asthma Network and Centers for Disease Control and Prevention report that up to 6% of the general population may be affected.) Other high-risk groups include restaurant workers, children with spina bifida, and anyone who has had several surgeries. In the United States alone, about 3 million people are allergic to latex. Repeated exposure to latex increases the likelihood of becoming allergic to it, which is why certain groups are at higher risk than others.

Latex is a by-product of milky sap from the rubber tree (Hevea brasiliensis), typically found in Vietnam, Indonesia, and Thailand.^[2] Before processing, it contains 60 polypeptides that are potentially allergenic, including 15 that have been conclusively identified as allergens.^[3]

The main allergenic polypeptides are as follows^[4]:

In spina bifida patients: Hev b 1 and 3;
In healthcare workers: Hev b 5 and 6, and secondarily, Hev b 2, 4, 7, and 13;
Associated with cross-reactivity with fruits*: Hev b 6.02 and 7; and
Panallergens, with unknown cross-reactivity: Hev b 8, 11, and 12.

*Cross-reactivity with foods, known as the "latex-fruit syndrome," occurs in some patients. The most severe triggers in those who are sensitive are avocado, banana, chestnut, and kiwi. Apple, carrot, celery, melons, papaya, and potato can produce a moderate reaction, and a number of other fruits, vegetables, and nuts may provoke a milder allergic reaction.

Hevea latex is a widely used material throughout the world and in several industries because it is versatile, flexible, and durable; resistant to moisture and chemicals; and low in cost. It is commonly found in toys, rubber bands, condoms, erasers, sports balls, and elastic goods. In the healthcare setting, it can be found in gloves, adhesives, catheters, syringes, stethoscopes, compression stockings, blood pressure cuffs, vial stoppers, electrode pads, masks, bandages, and medical tape.^[4]

Most reactions are to the rubber proteins, but some people may also be sensitive to the added chemicals in final products, said allergist and immunologist, Dr Purvi Parikh. "Adverse effects come in three varieties: irritant contact dermatitis, allergic contact dermatitis, and immediate-type allergic reactions."

Both types of dermatitis result in skin redness, lesions, or itching, and may take up to several days to manifest. The less severe of these two, irritant contact dermatitis, presents as a nonallergic, localized dermal inflammation, typically in reaction to the chemicals rather than to latex. Known as "type IV hypersensitivity," allergic contact dermatitis is a T-cell–mediated reaction to chemicals. Neither type of dermatitis tends to extend beyond the skin, although inflammation can weaken the dermal barrier, providing allergens with access to the body's internal tissues.

Type I hypersensitivities produce immediate allergic reactions to Hevea latex-specific immunoglobulin (Ig) E antibodies. This type of allergy, which Adele fan Dr Newman has, can be deadly, killing 1% of those who experience an attack. Histamine and leukotrienes are released from mast cells, causing itching, urticarial, asthma, papules, and anaphylaxis. Some people also experience bronchospasm, rhinitis, nausea, or vomiting.^[5]

No Such Thing as Latex-Free?

In response to these issues in the healthcare setting, there has been a trend toward making clinical environments "latex-free." Unfortunately, there is no single agreed-upon definition or criteria, and in fact, it may not be possible to provide an entirely latex-free area. Confusion has ensued Dr Parikh explained.

One obstacle has been an absence of regulation that would otherwise establish how products get labeled and what levels of latex will be defined as absence or presence. Fully aware of the challenges, the US Food and Drug Administration (FDA) strongly advised in an official statement that manufacturers refrain from labeling anything as "latex-free," or even stating that it "does not contain latex." Because so many materials do contain latex, or just the minute proteins that cause the allergic reactions, contamination is highly probable. "Not made with natural rubber latex" is a more accurate statement, because products made with polyvinyl chloride do not contain the offending proteins. However, even synthetic latex can cause allergic reactions in some people; they may be allergic to natural or synthetic latex, or both types.

If there is a serious concern, the only way to learn what is actually in a product is to call the manufacturer. Even then, there may be confusion.

Testing for Latex Allergies

"When there is a known risk or suspected allergy, routine testing is a viable option for both healthcare workers and their patients," Dr Parikh said. In the United States, testing methods include the patch test, glove application challenge, and IgE antibody immunoassays.

The patch test involves placement of typical latex chemicals on a patient's skin, where it remains for 2-3 days, and is then examined for visible reactions.

In the United States, IgE immunoassays, which detect the presence of Hevea latex-specific IgE antibodies in the serum of reactive patients, are currently the only test available for type I hypersensitivities. Neither intradermal testing or prick tests are FDA-approved, and these can only be performed outside of the United States.^[5]

Treating Latex Allergies

For dermal reactions, washing the area quickly provides the first line of defense. If irritation persists, topical corticosteroids and hydrating creams may be applied.

Life-threatening type I reactions demand immediate medical attention. The patient should be removed from the latex source as quickly as possible, into fresh, open air. If physical contact took place, the area should be rinsed off as vital signs are monitored and emergency treatment, such as an epinephrine autoinjector, is administered. Topical or oral steroids or antihistamines may also be given.

Sue Lockwood of the Allergy & Asthma Network stressed to Medscape that, even though a person might have only a mild reaction to latex most of the time, multiple, simultaneous, or more invasive exposure routes may yield a much more severe reaction. For example, latex or airborne proteins may come in contact with mucous membranes, intravenous entry points, or open wounds.

Precautions in the Clinical Setting

"Although ‘latex-free’ is probably not attainable," said Ms Lockwood, "clinicians can take precautions to reduce the risk of developing a latex allergy and to protect patients from reactions as well." Frequent handwashing, surface and floor cleaning, and removal of all known latex items can minimize risks. Reactive patients can also be scheduled for the first appointment of the day, making contamination after cleaning less likely.

Over the past few decades, several synthetic latex alternatives have been used to manufacture surgical gloves; these include silicone, neoprene, polyurethane, and vinyl, among others.^[2] Latex allergies have been decreasing among clinicians in recent years because of these alternatives,^[6] but precaution is still essential, because not all gloves or other materials are made to the same standards.^[5]

The best way to protect patients from unknown or known latex allergies is to ask questions about past exposures and subsequent reactions, use alternative materials whenever possible, and to adapt a "single-stick rule" for latex-stoppered vials in pharmacy and hospital settings. Eradication of allergic reactions to latex may not be possible, but a great reduction in the number of serious events that take place certainly is.^[4]