By Chuck Mills, CRNA
Allergies to natural rubber latex (NRL) affect between 8 percent and 25percent of healthcare workers (HCWs), especially nurses, exposed to productscontaining 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 systemreacts to proteins found in NRL. The immune system launches a 'defense' that cancause a host of unpleasant, and in some cases, life-threatening symptoms. It isthe same type of generalized allergic reaction seen when individuals, who areallergic to bee venom, receive a bee sting."
Although examination gloves cause most latex allergies, all hospital productsand supplies containing NRL, such as catheters, blood pressure cuffs andanesthesia equipment, can trigger reactions in sensitized individuals. For acomplete list of medical devices, products and equipment containing latex, visitthe American Association of Nurse Anesthetists (AANA) Web site at www.aana.comand access the "AANA Latex Allergy Protocol."
The first reported case of a latex allergy reported in medical literatureoccurred in 1979 to a British woman who developed a hypersensitivity to herhousehold rubber gloves. European medical journals record about 50 such casesbetween 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 duringthe past 20 years for several reasons. The introduction of standard precautions-- including the use of latex gloves by HCWs to prevent the spread of bloodbornediseases, such as AIDS, HIV and hepatitis B -- primarily contributed to the risein allergies seen after 1979. Increased awareness and reporting of latexallergies also revealed a higher prevalence of this hypersensitivity. Inaddition, insufficient washing during NRL glove manufacturing may havecontributed to a rise in latex allergies. In 1991, the Food and DrugAdministration (FDA) outlined to manufacturers a two-step washing process, thefirst to occur during leaching and the second after product completion, tobetter remove allergenic proteins from latex.
WHAT CAUSES LATEX ALLERGIES?
Contact with mucous membranes, regular glove wearing and inhalation ofaerosolized proteins represent the most common ways to contract a latex allergy.Ongoing exposure to products made from NRL or latex blends, especially skincontact with gloves, cause most allergic reactions. Surgical procedures causesome of the most severe reactions because latex comes into direct contact withmoist areas of the body and internal surfaces causing faster, easier absorptionof the allergen.
Airborne proteins, which enter the eyes or mucous membranes, also pose aserious health threat. Latex proteins bind with the cornstarch powder liningsome types of gloves, then become released into the air when wearers snap-offtheir gloves. B. Lauren Charous, MD, chair of the ACAAI's latex hypersensitivitycommittee, calls powdered NRL gloves "the chief source of latexaeroallergen in the medical setting."
ALLERGIC REACTIONS TO LATEX
The three recognized reactions to latex include non-allergic irritant contactdermatitis, type IV cell-mediated allergies and type I IgE-mediated allergies.
Non-allergic irritant contact dermatitis, a skin rash, is the most commonreaction affecting regular wearers of powdered and non-powdered latex gloves.Symptoms include dry, crusted patches in the glove area also caused by certaintypes of cleaners, repeated hand washing and incomplete hand drying.
Type IV cell-mediated allergies, the most common immune system reaction tolatex, affect 82 percent of individuals allergic to rubber products. A delayedhypersensitivity to one or more of the 300-plus chemicals used to manufacturelatex, type IV allergies produce allergic contact dermatitis within 48 to 96hours of exposure. Continued exposure puts individuals with a type IV allergy atrisk of developing the antibodies that can trigger a type I latex allergy.
Type I IgE-mediated allergies represent an immediate hypersensitivity toactual latex proteins and include two subgroups. The first causes hives, itchyand watery eyes, runny nose, sneezing, wheezing, asthma, abdominal pain, nausea,diarrhea and skin rashes. The second, and more serious, causes anaphylaxis, asevere immune system reaction characterized by breathing difficulties and lowblood 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 withdoctor-prescribed or over-the-counter ointments, creams or jellies. Patientsshould not use petroleum jelly and wear gloves at the same time since petroleumproducts destroy the barrier of protection provided by latex.
Patients with type IV allergies can use the aforementioned treatments torelieve skin irritations and should avoid the latex gloves or rubber productssuspected of causing the dermatitis.
Type I allergic reactions can only be treated by avoiding latex exposurealtogether. This requires healthcare workers to wear vinyl or non-latex glovesand work in areas that prohibit powdered glove use. The 1991 BloodbornePathogens Standard issued by the Occupational Safety and Health Administration (OSHA),states, "Glove liners, powderless gloves, or other alternatives must bereadily accessible to employees who are allergic to the gloves normallyprovided."
However, the use of powder-free gloves does not guarantee a safe environmentfor HCWs. Under current government standards, gloves labeled as powder-free cancontain up to 2 milligrams of powder per glove, enough to trigger allergicreactions in sensitized individuals. The following outlines steps that HCWs cantake to minimize their exposure to latex:
WAYS TO TREAT LATEX-SENSITIVE PATIENTS
HCWs need advance notice of a patient's latex sensitivity to provideeffective treatment and prevent medical complications. Patients should wear aMedic-Alert bracelet and charts should be clearly flagged. A crash cart stockedwith latex-free gloves and equipment, and drugs for treating anaphylaxis, shouldbe on hand.
If a patient experiences a severe latex reaction, HCWs should notifysupervisors and physicians, complete an incident report and document nursinginterventions taken. Healthcare workers should retain the product suspected ofcausing the reaction and follow hospital procedures to comply with the SafeMedical Devices Act.
The AANA's aforementioned latex allergy protocol contains avoidanceprecautions, patient care recommendations and emergency response and managementinformation. The protocol lists secondary pharmacological treatments,non-pharmacological considerations, pre-medication agents, and common medicaldevices, products and anesthesia equipment containing latex. It also providessuggested reading materials and the Web sites of manufacturers who offerlatex-free healthcare products.
WAYS TO DETECT LATEX ALLERGIES
Skin prick, skin patch and radioallergosorbent (RAST) tests screen for latexallergies. To perform the skin prick test, an allergist-immunologist injects thelatex proteins suspected of causing allergic reactions under the skin or to ascratch or puncture wound on the patient's arm or back. These proteins produce asmall, raised, red area within 15 minutes of injection among allergic patients.Skin prick tests, which can induce anaphylactic shock, should be performed onlyunder the supervision of an allergy specialist and with appropriate emergencyback-up equipment on hand.
Skin patch tests use the patient's glove or latex product to screen for animmediate or delayed hypersensitivity and to evaluate the cause of the skinirritation. Use of the latex product in question helps to ensure an accuratediagnosis since no standardized patch test exists.
The RAST test identifies specific IgE antibodies to latex in the blood andsupports a NRL allergy diagnosis. The diagnostic success of this test approaches100 percent.
The current unavailability of a standard by which to benchmark the skinprick, skin patch and RAST tests can produce inconclusive results, such as falsepositives and negatives. These inconsistencies may require further testing or adiagnosis to be based on a patient's medical history. The FDA is expected toapprove a serum for standardized skin prick testing soon.
CREATING A LATEX-SAFE HOSPITAL
Safeguarding the welfare of patients and healthcare workers may require thecombined efforts of industry, medical specialists, patient groups and governmentagencies according to the ACAAI which endorses content labeling for medicaldevices containing NRL and elimination of the word "hypoallergenic"from latex and non-latex glove descriptions.
Replacing latex examination gloves with non-latex substitutes represents aproactive step toward creating a safe environment for patients and providers.Although FDA figures indicate that synthetic rubber gloves exceed by more than105 percent the price of their NRL counterparts, many institutions saved moneyby 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 thosetransferring to patient care services. Part of a five-year NRL glove conversionplan, screening costs the institution $60,000 each year, but saves it more than$1 million in projected annual worker's compensation claims. Ordering one typeof latex-free gloves also proved more cost-efficient than ordering severaldifferent types of powdered and non-powdered latex gloves.
"An essential component of any institutional intervention program forNRL allergy is early detection. While the medical center is converting to anon-latex environment, we thought it was crucial to screen employees at risk sothat a safe work environment could be provided for them," explained MaryBeth Bollinger, MD, UMMC's director of pediatrics.
Chuck Mills is a certified registered nurse anesthetist (CRNA) and amember of the Occupational Safety and Hazard Committee for the AmericanAssociation of Nurse Anesthetists in Park Ridge, Ill.