Combatting Latex Allergies
By Chuck Mills, CRNA
Allergies to natural rubber latex (NRL) affect between 8 percent and 25 percent of healthcare workers (HCWs), especially nurses, exposed to products containing latex on a regular basis.
According to the American College of Allergy, Asthma and Immunology (ACAAI), "Latex allergy, or hypersensitivity, occurs when the body's immune system reacts to proteins found in NRL. The immune system launches a 'defense' that can cause a host of unpleasant, and in some cases, life-threatening symptoms. It is the same type of generalized allergic reaction seen when individuals, who are allergic to bee venom, receive a bee sting."
Although examination gloves cause most latex allergies, all hospital products and supplies containing NRL, such as catheters, blood pressure cuffs and anesthesia equipment, can trigger reactions in sensitized individuals. For a complete list of medical devices, products and equipment containing latex, visit the American Association of Nurse Anesthetists (AANA) Web site at www.aana.com and access the "AANA Latex Allergy Protocol."
The first reported case of a latex allergy reported in medical literature occurred in 1979 to a British woman who developed a hypersensitivity to her household rubber gloves. European medical journals record about 50 such cases between 1979 and 1988. In 1991, the U.S. Food and Drug Administration (FDA) received more than 1,000 reports of latex allergies.
The incidence of latex allergies among HCWs has increased dramatically during the past 20 years for several reasons. The introduction of standard precautions -- including the use of latex gloves by HCWs 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. In addition, insufficient washing during NRL glove manufacturing may have contributed to a rise in latex allergies. In 1991, the Food and Drug Administration (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.
WHAT CAUSES LATEX ALLERGIES?
Contact with mucous membranes, regular glove wearing and inhalation of aerosolized proteins represent the most common ways to contract a latex allergy. Ongoing exposure to products made from NRL or latex blends, especially skin contact with gloves, cause most allergic reactions. Surgical procedures cause some of the most severe reactions because latex comes into direct contact with moist areas of the body and internal surfaces causing faster, easier absorption of the allergen.
Airborne proteins, which enter the eyes or mucous membranes, also pose a serious health threat. Latex proteins bind with the cornstarch powder lining some types of gloves, then become released into the air when wearers snap-off their gloves. B. Lauren Charous, MD, chair of the ACAAI's latex hypersensitivity committee, calls powdered NRL gloves "the chief source of latex aeroallergen in the medical setting."
ALLERGIC REACTIONS TO LATEX
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 also 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. A delayed hypersensitivity to one or more of the 300-plus chemicals used to manufacture latex, type IV allergies produce 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 second, and more serious, causes anaphylaxis, a severe immune system reaction characterized by breathing difficulties and low blood pressure that can cause shock or even death.
WAYS TO TREAT AND PREVENT LATEX ALLERGIES
Though no cure exists, non-allergic skin rashes can be treated with doctor-prescribed or over-the-counter ointments, creams or jellies. Patients should not use petroleum jelly and wear gloves at the same time since petroleum products destroy the barrier of protection provided by latex.
Patients with type IV allergies can use the aforementioned treatments to relieve skin irritations and should avoid the latex gloves or rubber products suspected of causing the dermatitis.
Type I allergic reactions can only be treated by avoiding latex exposure altogether. This requires healthcare workers to wear vinyl or non-latex gloves and work in areas that prohibit powdered glove use. The 1991 Bloodborne Pathogens Standard issued by the Occupational Safety and Health Administration (OSHA), states, "Glove liners, powderless gloves, or other alternatives must be readily accessible to employees who are allergic to the gloves normally provided."
However, the use of powder-free gloves does not guarantee a safe environment for HCWs. 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. The following outlines steps that HCWs can take to minimize their exposure to latex:
- Wear low-protein or powder-free gloves.
- Reduce the amount of time gloves are worn.
- Wash hands with a pH-balanced soap and dry thoroughly between glove use to remove latex proteins and prevent skin irritations.
- Avoid oil-based hand creams and lotions, which deteriorate gloves and accelerate the release of latex allergens.
- Remove gloves hourly to allow hands to air-dry.
- Avoid snapping off gloves to prevent the release of airborne latex proteins.
- Replace latex gloves with appropriate substitutes such as vinyl gloves.
- Wear glove liners made of cotton or polymers, like hydrogel and silicone, under latex gloves.
- Double or triple glove to reduce latex protein exposure to co-workers and patients.
- Remove latex-containing dust from the workplace.
WAYS TO TREAT LATEX-SENSITIVE PATIENTS
HCWs need advance notice of a patient's latex sensitivity to provide effective treatment and prevent medical complications. Patients should wear a Medic-Alert bracelet and charts should be clearly flagged. A crash cart stocked with latex-free gloves and equipment, and drugs for treating anaphylaxis, should be on hand.
If a patient experiences a severe latex reaction, HCWs should notify supervisors and physicians, complete an incident report and document nursing interventions taken. Healthcare workers should retain the product suspected of causing the reaction and follow hospital procedures to comply with the Safe Medical Devices Act.
The AANA's aforementioned latex allergy protocol contains avoidance precautions, patient care recommendations and emergency response and management information. The protocol lists secondary pharmacological treatments, non-pharmacological considerations, pre-medication agents, and common medical devices, products and anesthesia equipment containing latex. It also provides suggested reading materials and the Web sites of manufacturers who offer latex-free healthcare products.
WAYS TO DETECT LATEX ALLERGIES
Skin prick, skin patch and radioallergosorbent (RAST) tests 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 identifies specific IgE antibodies to latex in the blood and supports a NRL allergy diagnosis. 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 based on a patient's medical history. The FDA is expected to approve a serum for standardized skin prick testing soon.
CREATING A LATEX-SAFE HOSPITAL
Safeguarding the welfare of patients and healthcare workers may require the combined efforts of industry, medical specialists, patient groups and government agencies according to the ACAAI which endorses content labeling for medical devices containing NRL and elimination of the word "hypoallergenic" from latex and non-latex glove descriptions.
Replacing latex examination gloves with non-latex substitutes represents a proactive step toward creating a safe environment for patients and providers. Although FDA figures indicate that synthetic rubber gloves exceed by more than 105 percent the price of their NRL counterparts, many institutions saved money by converting to a latex-free environment.
In 1998, the University of Maryland Medical Center (UMMC) in Baltimore, adopted a mandatory latex allergy screening policy for new employees and those transferring to patient care services. Part of a five-year NRL glove conversion plan, screening costs the institution $60,000 each year, but saves it more than $1 million in projected annual worker's compensation claims. Ordering one type of latex-free gloves also proved more cost-efficient than ordering several different types of powdered and non-powdered latex gloves.
"An essential component of any institutional intervention program for NRL allergy is early detection. While the medical center is converting to a non-latex environment, we thought it was crucial to screen employees at risk so that a safe work environment could be provided for them," explained Mary Beth Bollinger, MD, UMMC's director of pediatrics.
Chuck Mills is a certified registered nurse anesthetist (CRNA) and a member of the Occupational Safety and Hazard Committee for the American Association of Nurse Anesthetists in Park Ridge, Ill.