by Chuck Mills, CRNA
In 1997, a television news program tipped-off Sarah Dufault, a registered dental hygienist from Lancaster, Pa., that she might be suffering from an acute allergy to natural rubber latex (NRL). The program, which profiled workers suffering with NRL allergies, struck a chord with Dufault, who recalled experiencing reactions to latex gloves as far back as 1985. Later, she developed "horrible sinus problems and coughing," a condition her ear, nose and throat doctor sought to correct through surgery. The TV program helped to make sense of these seemingly unrelated symptoms and renewed hope for Dufault, on the verge of giving-up a successful 26-year career as a dental hygienist.
"I was ready to stop working five years ago, when I saw a "20/20" program that interviewed several people with latex allergies," she said. "I thought, 'I can't have this. This can't be happening to me.'"
At the behest of Dr. Lise Borel, executive director of ELASTIC, a national latex allergy awareness organization based in West Chester, Pa., Dufault sought the help of an allergist to help piece together her disparate symptoms. In 1997, the specialist diagnosed her condition as a type I allergy to NRL. Dufault, who claims no family history of allergies, not even seasonal ones, attributes her condition to occupational NRL exposure.
Latex allergies have risen dramatically over the past 20 years for several reasons. The introduction of universal precautions — including the use of latex gloves to prevent the spread of bloodborne diseases such as AIDS, HIV, and hepatitis B — primarily contributed to the rise in allergies seen after 1979. Increased awareness and reporting of latex allergies also revealed a higher prevalence of this hypersensitivity.
Insufficient washing during NRL glove manufacturing also may have contributed to an increase in latex allergies. In 1991, the FDA outlined to manufacturers a two-step washing process, the first to occur during leaching and the second after product completion, to better remove allergenic proteins from latex.
Latex allergies often trigger food cross-reactions because certain plant products — including bananas, avocados, kiwis, plums, peaches, cherries, apricots, figs, papayas, tomatoes, potatoes, and chestnuts — contain the same allergy-producing proteins as NRL. Latex-sensitive individuals should avoid the aforementioned fruits, vegetables, and nuts, as well as genetically engineered fruits and vegetables that contain the same DNA markers as latex.
Treating and preventing allergies
Though no cure exists, non-allergic skin rashes can be treated with doctor-prescribed or over-the-counter ointments, creams, or jellies. Petroleum jelly should not be applied before glove use since petroleum products can destroy the barrier of protection provided by latex.
Individuals with type IV allergies can use the aforementioned treatments to relieve skin irritations. They also should avoid the latex gloves or rubber products suspected of causing the dermatitis.
Those with type I allergies must avoid latex exposure altogether. This requires them to wear vinyl or non-latex gloves and work in areas that prohibit powdered glove use.
In 1991, the U.S. Occupational Safety and Health Administration issued a bloodborne pathogen standard stating that "Glove liners, powderless gloves, or other alternatives must be readily accessible to employees who are allergic to the gloves normally provided." Latex-sensitive individuals should be aware that the use of powder-free gloves does not guarantee a safe environment. Under current government standards, gloves labeled as "powder-free" can contain up to 2 milligrams of powder per glove, enough to trigger allergic reactions in sensitized individuals.
Skin prick, skin patch, and radioallergosorbent tests (RAST) screen for latex allergies. To perform the skin prick test, an allergist-immunologist injects the latex proteins suspected of causing allergic reactions under the skin or to a scratch or puncture wound on the patient's arm or back. These proteins produce a small, raised, red area within 15 minutes of injection among allergic patients. Skin prick tests, which can induce anaphylactic shock, should be performed only under the supervision of an allergy specialist and with appropriate emergency back-up equipment on hand.
Skin patch tests use the patient's glove or latex product to screen for an immediate or delayed hypersensitivity and to evaluate the cause of the skin irritation. Use of the latex product in question helps to ensure an accurate diagnosis since no standardized patch test exists.
The RAST test, which identifies specific IgE antibodies to latex in the blood, can accurately diagnose an NRL allergy. The diagnostic success of this test approaches 100 percent.
The current unavailability of a standard by which to benchmark the skin prick, skin patch and RAST tests can produce inconclusive results, such as false positives and negatives. These inconsistencies may require further testing or a diagnosis to be made based on a patient's medical history. The Food and Drug Administration (FDA) is expected to approve a serum for a standardized skin prick test soon.
Dental health workers
A survey in the January 1996 issue of the Journal of the American Dental Association, estimates the rate of latex allergies among dental workers to be about 12 percent. Latex, which abounds in dental settings, can be found in items ranging from dental dams and suction lines to chair coverings and gaskets.
Wearing non-latex or powder-free gloves represent "the most important latex-reduction method" according to information contained in the January 2001 issue of In Control, a supplement published by the U.S. Air Force Dental Investigation Service. In Control, which covers "issues in infection control and occupational health and safety in dentistry," recommends that dental health workers take the following precautions to avoid developing latex allergies:
• Reduce the use of gloves in the general population.
• Urge manufacturers to wash allergens out of latex gloves.
• Suggest to healthcare providers that they schedule latex-sensitive patients as the first case of the day because latex is an aeroallergen and stays in the air for at least an hour after latex gloves are used.
• Emphasize to patients that they need to tell physicians, dentists, employers, and school officials about their latex allergy. Patients with latex allergies should be advised to wear a medical alert bracelet.
• Emphasize to hospitals and clinics that questions about latex sensitivity should be included in all patient histories and that clear, visible signs be placed on doors to patient and procedure rooms when there is a latex-sensitive patient present.
• Due to the risk of anaphylaxis, emphasize the need for latex-safe resuscitation equipment.
• Advise patients to carry auto-injectable epinephrine and to avoid foods that cross-react with latex, such as bananas, kiwis, and avocados.
• Distribute information about latex allergy to all healthcare employees, students, ancillary personnel and patients and encourage them to read labels to identify latex-containing items.
Converting to a latex-safe practice
To reduce the incidence of latex allergies among patients and staff, some dentists opt to convert their practices to latex-safe. Latex-safe describes an environmental standard that eliminates significant exposure factors, both direct and indirect, that can cause latex allergies. Latex-safe should not to be confused with latex-free, a term reserved for products that contain no NRL.
Dr. Jeffrey S. Harris, who runs the Chadds Ford Center for Cosmetic and Restorative Dentistry in Chadds Ford, Pa., converted his practice to latex-safe in 1996 out of concern for "the well-being of myself, my patients and my staff." Harris, who "developed a contact dermatitis to a face mask," said his dental assistant suffered allergies to latex gloves. The conversion, which took about a year and a half, consisted of replacing the carpeting, heating, ventilation and air conditioning (HVAC) duct work, cleansing the walls and floors, professional air-filtration vacuuming, and conducting inventory analysis.
"I went as far as changing the furniture and carpeting in the waiting room and the entire HVAC system has been replaced. I continued to work with dental manufacturers to make sure their products contained no latex. I talked to the tech support people to ensure that the O-rings and hoses were made of silicon and vinyl, not rubber," explained Harris.
The conversion cost about $19,000 including the HVAC replacement, which, Harris says, "I was planning to do anyway because I wanted a better system." He believes the remaining $6,000 spent on inventory and office items "is well within the budget of the average practitioner" and represents a long-term investment "that benefits the health of the practitioner and his/her staff."
Dr. Larry C. Smedley, an orthodontist with offices in West Chester and Downingtown, Pa., converted his practices to latex-safe six years ago. Smedley, who took stock of his supplies "to find out what's made of latex," says "there are a lot of little details needed to make an office latex-safe." He adds that adjusting to the feel of non-latex gloves proved an initial challenge for his staff, accustomed to wearing latex gloves.
"The first three or four months, the assistants didn't like the gloves," Smedley said. "Now, it's not a big deal. Because we don't use the tips of our fingers the way healthcare workers do, it's easier for us to adapt to non-latex gloves."
Harris encourages his colleagues to establish latex-safe practices, noting that the long-term health benefits outweigh the short-term costs. Harris reaped a "10-fold return on my $19,000 investment in one year" from latex-sensitive patient referrals. He now sees patients who come from "as far west as Michigan and as far south as Florida because they can't be treated anywhere else in the country."
Smedley speculates that many dentists forgo latex-safe conversion because of the non-invasive nature of their practices. Nevertheless, he advises orthodontists to practice latex-safe to protect their patients against the repeat exposure caused by multiple annual appointments.
"Orthodontists see patients 15 to 20 times over a two-year period. The more we expose the public to latex, the better the chance that we will make them latex-sensitive," commented Smedley.
Dufault credits a latex-safe dental practice with saving her career and allowing her to continue to practice dental hygiene. Unable to moonlight at offices that use latex gloves, she now works exclusively for a father and son dental team in Lancaster, Pa. Employed there for 10 years, she reports no allergy symptoms.
"I have had no reaction whatsoever in this office," she said. "Just as the person allergic to tree pollen has no problem when it is no longer in the air, I have no problem when the allergen is not present in my working environment."
Chuck Mills is a certified registered nurse anesthetist (CRNA) and member of the Occupational Safety and Hazard Committee for the American Association of Nurse Anesthetists in Park Ridge, Ill. Mills maintains an anesthesia management consulting and health-care law practice in Saunderstown, R.I.What are latex allergies?
Latex allergies represent an antigenic response to the complex compounds known as proteins found in NRL. More than a dozen proteins identified in NRL can cause allergic reactions, though which one(s) remains uncertain. Latex proteins react with the body's IgE antibodies, a group of structurally related human serum proteins responsible for allergies, to produce a host of unpleasant symptoms. These include sneezing, wheezing, watery eyes, skin rashes and anaphylaxis.
The three recognized reactions to latex include non-allergic irritant contact dermatitis, type IV cell-mediated allergies, and type I IgE-mediated allergies. Non-allergic irritant contact dermatitis, a skin rash, is the most common reaction affecting regular wearers of powdered and non-powdered latex gloves. Symptoms include dry, crusted patches in the glove area. These symptoms also are caused by certain types of cleaners, repeated hand washing and incomplete hand drying.
Type IV cell-mediated allergies, the most common immune system reaction to latex, affect 82 percent of individuals allergic to rubber products. Type IV latex allergies represent a delayed hypersensitivity to one or more of the 300-plus chemicals used to manufacture latex and cause allergic contact dermatitis within 48 to 96 hours of exposure. Continued exposure puts individuals with a type IV allergy at risk of developing the antibodies that can trigger a type I latex allergy.
Type I IgE-mediated allergies represent an immediate hypersensitivity to actual latex proteins and include two subgroups. The first causes hives, itchy and watery eyes, runny nose, sneezing, wheezing, asthma, abdominal pain, nausea, diarrhea, and skin rashes. The more serious second subgroup causes anaphylaxis.