Looking Out for Latex
By Sandra A. Holmes
As students with medical conditions are mainstreamed into classrooms across the nation, the possibility of a student with a latex allergy both diagnosed and undiagnosed that could cause a life-threatening situation increases. In my own classroom, a student who was unaware she was latex sensitive experienced a severe Type 1 allergic reaction to rubber bands during an activity. As a result of this experience, I realized that as a teacher, I needed to know more about this condition. I’d like to share the information I have discovered with colleagues who will undoubtedly interact with students who have latex allergies.
I was amazed at how many latex products all of us are exposed to on a daily basis. More than 40,000 products contain latex. Thus, eliminating their presence from the classroom setting is extremely difficult. A continuing concern is that every first-aid kit contains latex gloves. It is easy to imagine that as one uses latex gloves to prevent the transmission of disease, one could also be responsible for a death from latex reaction in a sensitive student. (See Table 1 on pages 24 and 25 for a list of products commonly found in a classroom setting that contain latex and, if known, have a substitute.)
The first incidents of latex allergy in the United States were reported in 1988. Numbers had increased to at least 500,000 by 1992. Published estimates, based on medical testing, indicate 17 million adults in the general U.S. population are affected by Type 1 latex allergy, the most severe category (Cornish and Siler, 1996).
Between 1990 and January 1991, nine children at a children’s hospital in Milwaukee had anaphylactic reactions within 30 minutes after general anesthesia was started, but before any surgical incisions had been made. The latex connection was the anesthesia equipment and intravenous catheters. Eight of the children required intensive care. (Stehlin, 1992; Anonymous, 1996-A; Jancin, 1992; Sussman and Beezhold, 1995; American Academy of Allergy and Immunology, 1963).
Preliminary reports of a nationwide survey of children’s hospitals have identified at least 25 other institutions that have reported similar reactions since January 1990. All 75 children who had anaphylactic reactions had either spina bifida or other conditions involving the genitourinary tract. (Anonymous, 1996-A; Jancin, 1992; Meeropol, Leger, and Frost, 1993; Shapiro, Kelly, Setlock, Suwalski, and Meyers, 1992; Young, Meyers, McCulloch, and Brown, 1992).
What is Latex?
If latex is needed, the tapper adds a stabilizing agent, usually ammonia, which prevents the latex from coagulating. The raw liquid is poured into containers and delivered to a processing station where it is strained and concentrated. At no stage is the latex heated. This means the proteins remain in the latex.
If solid rubber is required, the cup lump, together with bits and pieces of latex on the bark and ground, are collected together and processed. This processing involves heat, which destroys many (but not all) of the proteins and produces solid rubber.
Increase in Allergies
New and inexperienced glove manufacturers entered the market and short-cuts in manufacturing became common in order to supply the increased demand (Bodycoat, 1993). Altered manufacturing processes included reduction and sometimes elimination of the leaching step normally used to wash the latex products (Bodycoat, 1993; Russell-Fell, 1993). This washing process removes soluble latex compounds as well as chemical additives. Underwashed products contain high levels of Hevea brasiliensis latex proteins, which cause allergic reactions in some people.
In May 1991, the FDA outlined a letter to all manufacturers of latex medical devices to use a two-step washing procedure — first during the production leaching process and again after the product is completed — to remove many of latex’s allergenic proteins. In June 1997, the National Institute for Occupational Safety and Health (NIOSH) released a NIOSH Alert “warning sheet” for workers exposed to latex and other products containing natural rubber latex. The document lists products containing latex, recommendations for preventing latex allergies in the workplace, and references on latex allergies (NIOSH, 1997; Bubak, 1992; Jancin, 1992). In the past decade, the FDA received in excess of 1,700 reports of severe allergic reactions, including 16 deaths in children related to medical devices containing latex (Anonymous, 1998).
Latex-free synthetic rubber, such as neoprene, nitrile, SBR, Butyl, and Vitron are polymers that are available as alternatives to natural rubber. There are no naturally occurring proteins in them, and they are NOT responsible for latex allergy (Cornish and Siler, 1996).
What Is Latex Allergy?
Type 4 reactions are limited to the exposed area and are identified as contact dermatitis or as allergic contact dermatitis. Symptoms include the development of dry, itchy, red, irritated areas on the skin, usually the hands. Allergic contact dermatitis results from exposure to chemicals added to latex during harvesting, processing, or manufacturing. These chemicals can cause skin reactions similar to those caused by poison ivy. Other Type 4 reactions include itching/burning/irritated eyes, runny nose, wheezing, or blisters on the hands. The blisters may spread away from the area of skin touched by the latex. Symptoms may occur anywhere from 24 to 48 hours after exposure. Because reactions vary, there is no standard time frame for when symptoms start to go away.
A Type 1 hypersensitive reaction represents a broad spectrum of symptoms and is identified as a systemic reaction. Although the amount of exposure needed to cause sensitization or symptoms is not known, exposure even at low levels can trigger allergic reactions in sensitive individuals.
Reactions usually begin within minutes of exposure to latex, but they can occur hours later and can produce various symptoms. Very mild symptoms include skin redness, hives, or itching. More severe reactions may include respiratory symptoms such as a runny nose and watery eyes, sneezing, itchy eyes, scratchy throat, and asthma.
Very severe cases can include an anaphylactic episode, a response the body has to a mass allergen exposure. In this case, skin rash, itching, hives, swollen red skin, tears, itching or burning eyes, swollen lips and tongue with difficulty breathing or wheezing, asthma, shortness of breath, dizziness, fainting, abdominal pain, nausea, and diarrhea can occur and be life threatening.
In rare cases, an allergic individual goes into shock. Blood pressure plummets, the throat swells, and the airways in the lungs constrict. This kind of reaction can be the result of inhaling latex particles that are in the air or introducing latex through direct contact with rubber products. Without immediate treatment, the person will die. A shot of epinephrine — the same drug used to treat severe allergic reactions to bee stings — will counteract the shock if given immediately (Slater, 1989; Sussman and Beezhold, 1995; American Academy of Allergy and Immunology, 1993).
Determining Latex Sensitivity
The following foods cross-react with latex: avocados, bananas, pineapples, apricots, grapes, kiwis, tomatoes, papayas, passion fruit, cherries, figs, peaches, nectarines, plums, celery, raw potatoes, hazelnuts, and chestnuts. Bananas have the highest cross-reactivity correlation to latex allergies (Ozment, 1997; National Information Center for Children and Youth with Disabilities (NICHCY), telephone conversation with author).
Identifying a sensitivity to latex is determined from a review of past medical history, a physical exam, and blood tests. Three FDA-approved blood tests for latex-specific IgE antibodies are now used. Test results define the presence of sensitivity. Once a sensitivity is present, IgE antibodies cannot be used to predict how severe a reaction will occur.
A latex allergy, like all allergies, occurs with exposure to the allergen. This progressive allergy worsens with increased exposure to latex (Sussman and Beezhold, 1995; American Academy of Allergy and Immunology, 1993).
Who Is at Risk?
Patients, especially special needs children who have multiple repeated exposures to latex, usually through mucosal exposure, are at a higher risk for developing latex allergy. The Spina Bifida Association of America and the FDA estimate that as many as 65 percent of children with spina bifida have latex allergy. Lesser incidences, but still above 25 percent, occur in all patients (any age) with spinal injuries (up to 25 percent) and children with multiple congenital defects (33 percent), especially urinary tract defects, and any child who has had three or more surgeries (children with spina bifida have surgeries very early in life) (3 percent). It is the repeated exposure to latex (usually through catheterization) that sensitizes people to latex (Ozment, 1997; Sussman and Beezhold, 1995; American Academy of Allergy and Immunology, 1993).
Contact may come from unexpected sources, such as fast food workers preparing an order. The list of examples is endless (see Table 1 on pages 24 and 25). The accuracy of this list cannot be relied upon 100 percent because manufacturers change their products frequently. If you are in doubt, check by calling the manufacturer to verify absence of latex (Ozment, 1997; NICHCY, telephone conversation with author).
I have identified products in the professional setting that impacted my student with a latex allergy. Not only did I need to redesign many activities and projects for her, but the entire school setting had to be evaluated for latex products.
Everything from the welcome mat at the entrance to the school to the gaskets that fixed the leaky school faucets caused reactions. When the school driveway was being treated with sealant, she had a moderate asthmatic reaction. During finger-painting activities, she had to wear nonlatex gloves, such as vinyl, neoprene, or polymer gloves. The clothing, toys in the room, and items brought in for sharing time had to be carefully screened. Plugging in the VCR to show a videotape included contact with the latex-coated electrical cord. Pen grips, erasers on the end of a pencil, personal hygiene products in the bathroom, and touch-tone telephone keypads became allergy issues.
From transportation on field trips to computer mouse pads, cosmetics for Halloween makeup and school plays to hands-on materials for activities — it was incredible all that needed to be evaluated for latex. The information in Table 1 is offered as a guide to others who must face the same situations or are learning that they themselves are sensitive to latex.
As more students with special needs and complicated medical histories become members of classrooms, the likelihood of a severe latex reaction will increase and unless quick medical assistance is provided, a death could occur. Awareness of the numerous sources of latex in the classroom environment will help all teachers evaluate the materials they select for classroom and laboratory experiences and perhaps encourage the use of alternate materials that will not contribute to a possible reaction.
Table 1. Products that Contain Latex and Their Alternatives. [Omitted]
Sandra A. Holmes is an assistant professor of science education at Messiah College in Grantham, Pennsylvania.
Reprinted with permission from NSTA Publications, © 1999
from Science and Children, National Science Teachers Association
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