Q & A: Latex AllergiesThe incidence of serious allergic reactions to latex has increased dramatically in recent years. In rare cases, these allergies can be fatal. Health care workers and others who are frequently exposed to products containing latex should be aware of the potential for developing an allergic reaction, and individuals who exhibit symptoms of the allergy should be alerted to the need to avoid future exposure to latex products. About Latex AllergyWhat is latex allergy?Latex allergy, or hypersensitivity, occurs when the body’s immune system reacts to proteins found in natural rubber latex. 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. What triggers the immune system’s reaction to latex? Some individuals have specific antibodies, called IgE antibodies, that make them hypersensitive to the proteins in natural rubber latex. IgE-mediated reactions to latex proteins are responsible for most and for the most severe allergic reactions to latex. Also, various chemicals that are added to latex during processing may be responsible for some local skin reactions, but these additives have not been implicated in the more generalized, potentially fatal allergic reactions associated with latex. About Natural Rubber LatexWhat is natural rubber latex?Natural rubber latex is a processed plant product derived almost exclusively from the tree hevea braziliensis found in Africa and Southeast Asia. Natural rubber latex should not be confused with butyl- or petroleum-based synthetic rubbers. Synthetic products, including latex house paints, have not been shown to pose any hazard to latex-sensitive individuals. What products contain latex? Latex is a common component of many medical supplies, including disposable gloves, airway and intravenous tubing, syringes, stethoscopes, catheters, dressings and bandages. Many of these medical devices come into contact with mucous membranes, which enhances the absorption of latex proteins that can trigger an allergic reaction. Latex gloves also frequently are implicated in allergic reactions due to the repeated direct exposure of the wearer’s hands to latex proteins or due to airborne latex proteins that are absorbed by powders used to line some latex gloves. While latex also is found in as many as 40,000 consumer products, including condoms, balloons, athletic shoe soles, tires, underwear leg and waist bands, rubber toys, nipples and pacifiers, these rarely cause problems except to the most sensitive patients. Symptoms of Latex AllergyWhat are the symptoms of latex allergy?Allergy to latex proteins is a new medical problem with symptoms similar to those seen in individuals who are allergic to bee venom or cat dander. Reactions on exposure to the allergen are generally acute and may mimic hay fever or asthma, with symptoms such as nasal congestion, hives or difficulty breathing. The most severe cases can result in anaphylaxis, a potentially fatal reaction that affects many parts of the body at once. Symptoms are usually immediate, progress rapidly and may include a dangerous drop in blood pressure, flushed skin, difficulty breathing, swelling of the throat, tongue and nose, and loss of consciousness. Emergency medical attention should be sought at the first sign of an anaphylactic reaction. Skin problems resulting from the use of latex and non-latex gloves are frequently confused with latex allergy. Contact dermatitis is a frequent problem in glove wearers which can be due to an irritant contact dermatitis caused by frequent hand-washing and drying with irritating soaps, skin abrasions from donning and removing gloves and maceration of skin covered by an impermeable barrier. It can also be due to a “chemical sensitivity” dermatitis caused by a contact allergy to one of the chemicals used in the production of rubber gloves. These local skin problems are virtually never a result of true latex allergy. How do the symptoms develop? In most cases, latex allergy develops after repeated exposures to latex. It should be noted, however, that direct physical contact with latex-containing products is not needed to trigger the allergic reaction. Cases of anaphylaxis have resulted from inhaling latex proteins, which can be absorbed by the powder that is used to line some latex gloves. When the gloves are snapped on and off, the proteins become airborne and can pose a risk to some individuals with latex hypersensitivity. Prevalence of Latex AllergyHow common is latex allergy?It is difficult to say how widespread the problem of latex allergy may be. Approximately 1,000 cases of allergic or anaphylactic reactions to latex-containing medical products have been reported to the U.S. Food and Drug Administration (FDA) since 1988. It is assumed that many other cases go unreported. In one 1994 study, 6 percent of volunteer blood donors were found to have increased levels of anti-latex IgE antibodies, although many of the volunteers did not show symptoms of latex allergy. Other research suggests that more than 100,000 health care workers may be at risk for developing latex allergy. Why is the incidence of latex allergy increasing? The introduction of universal precautions in health care settings including the widespread use of latex gloves to prevent the spread of AIDS and hepatitis B is believed to be the primary cause of the increased prevalence of latex allergy. Also, there is greater awareness and reporting of latex allergy than in the past. Individuals at RiskWho is at greatest risk for latex allergy?The greatest risk is to individuals who are repeatedly exposed to products containing latex, particularly:
The risk of anaphylaxis appears to be greatest in individuals with prior allergic reactions to latex-containing objects or prior, unexplained reactions or anaphylaxis during a medical or surgical procedure. Health care providers with a history of severe or worsening latex-glove-induced eczema, hives or work-related rhinitis or asthma-like symptoms should be especially cautious. Preventing Latex AllergyHow can latex allergy be prevented?All products and medical devices that come in contact with individuals at risk should be reviewed for possible latex content. A label of “hypoallergenic” does not mean that a product is latex-free. In general, only low allergen, preferably non-powdered latex gloves should be used. The powders that are used in some latex gloves can absorb latex proteins and carry them into the air where they may be inhaled by latex-sensitive individuals. How can health care workers who must wear rubber gloves to protect themselves from transmissible disease protect themselves from developing latex hypersensitivity? Health care workers with a history of latex sensitivity must stop wearing latex gloves and their co-workers must not use powdered gloves. Care should be exercised in the choice of substitutes, since all synthetic or non-latex products are not equally impermeable to blood-borne pathogens. Health care workers with a history of glove-associated skin irritations, or contact dermatitis, should use alternative gloves (which may include latex gloves) and topical treatments to relieve their symptoms. Some petroleum-based products have been shown to compromise the barrier function of latex gloves, and care should be taken in the choice of treatments used to relieve contact dermatitis. What else can be done to protect against latex allergy? The FDA in June 1996 proposed mandatory labeling of latex rubber in medical devices and banning of the term “hypoallergenic” on latex-containing medical devices, requirements that have been urged by the American College of Allergy, Asthma & Immunology. The College also has proposed that the FDA and other government agencies:
Diagnosis and TreatmentHow is suspected latex allergy confirmed?A skin prick test may be done for latex allergy, but there are currently no licensed reagents commercially available for the test. Because of the potential for a life-threatening anaphylactic reaction to the test itself, skin prick tests for latex allergy should be performed only under the close supervision of an allergy specialist. An allergist-immunologist also can perform a blood test to confirm the presence of IgE anti-latex antibodies. Skin patch tests are used to evaluate the cause of skin irritations, or contact dermatitis, caused by rubber gloves. How are latex allergies treated? There are a number of medications available to treat the symptoms of latex allergy once it develops. However, because there is no cure yet, the best “treatment” is prevention. An allergy specialist can provide more information on how to manage allergic reactions to latex. ACAAI American College of Allergy, Asthma & Immunology 85 West Algonquin Road, Suite 550 Arlington Heights, IL 60005 Phone: (847) 427-1200 Fax: (847) 427-1294 Reproduced here with permission. |
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