Published: August 2010
The dramatic surge in the incidence of latex allergy in the 1980s is believed to be related to increased use of latex gloves after the adoption of universal precautions and to manufacturing changes that might have exposed health care workers and patients to latex gloves with higher latex content. Recognition of latex allergy as a public health concern led to identification of populations at risk, defined clinical symptoms, and recommendations for evaluation and management.1 In addition, guidelines for preventing new cases of latex allergy and for safety of latex-allergic patients were established.2 The major thrust of these policies is the restricted use of latex gloves, and the promotion of the use of nonpowdered sterile latex gloves to establish latex-safe environments in the hospital setting. Manufacturers of medical and commercial products have responded by labeling latex products and by developing latex-free items. These efforts to decrease latex exposure appear to have been successful in decreasing rates of sensitization and allergic reactions to latex.3
Latex allergy is defined as the presence of specific immunoglobulin E (IgE) antibody to latex proteins in persons who have a variety of clinical symptoms to latex-containing products. The cause of latex allergy involves exposure and sensitization to the latex, which is derived from the sap of the rubber tree (Hevea brasilienses) and is harvested primarily in Malaysia, Indonesia, and Thailand.
Exposure to latex can occur by contact with skin, mucous membranes, or blood. Sensitization to latex proteins depends on the amount and duration of exposure and the predisposition to atopy, and it is defined as identification of specific IgE antibody to latex proteins, with or without clinical symptoms. Allergy is defined by sensitization and clinical symptoms. Prevalence rates of latex allergy or sensitization have varied from population to population. The highest rates are found in patients with spina bifida and other congenital urogenital anomalies (24%–60%), moderate rates are found in health care workers and employees in the rubber industry (5%–15%), and the lowest rates are found in the general population (1%).4 Irritant dermatitis may be another risk factor for the development of immunologic reactions to latex because the protective skin barrier is altered and allergen exposure and absorption may be increased, leading to possible IgE sensitization.
Latex allergy is caused by latex allergens cross-linking specific IgE antibodies located on allergic effector cells, mast cells, and basophils. This action activates the cells to release preformed mediators, such as histamine, which cause immediate clinical symptoms of allergy, notably sneezing and itching. Activated mast cells also are responsible for the production of newly formed mediators (prostaglandins and leukotrienes) and cytokines (interleukin [IL]-4, IL-13, and tumor necrosis factor [TNF]-α), which contribute to more chronic symptoms of allergy such as nasal congestion and swelling of tissues. More severe clinical manifestations of latex allergy, such as anaphylaxis, are also related to the release of these allergic cell mediators and their effects on vasculature, leading to vasodilation and subsequently to hypotension.
Signs and symptoms of latex allergy depend on the type of latex product, the route of exposure, the amount of latex proteins, and the level of individual allergic sensitivity. Symptoms can vary from mild itching and urticaria, to rhinitis and asthma, to anaphylaxis. Latex gloves are probably the primary source of exposure, because they are used in many professions, including medicine, dentistry, housekeeping, daycare, and beauty and food services. This wide range of use can cause symptoms not only in persons wearing gloves but also in persons exposed to those wearing the gloves.
The most common adverse reactions experienced by persons wearing latex gloves are irritant reactions, typically erythema, cracking, dryness, and chapping of the skin. These reactions occur without an immunologic mechanism. Damage to the skin can occur by physical trauma with glove wearing, prolonged contact with solvents trapped underneath the gloves, extremes of skin temperature, and sweating.
Allergic contact dermatitis from latex gloves requires lymphocyte sensitization to chemical additives or accelerators that are used in the manufacturing process. The onset of symptoms is typically 24 to 48 hours after contact, and the symptoms are representative of contact dermatitis, including pruritus, erythema, blisters, or vesicles. Chronic symptoms include scaling, dryness, cracking, and thickening of the skin. Thiurams, carbamates, and benzothiazoles can be confirmed as allergens by patch testing.5
Immediate hypersensitivity reactions to latex allergens, otherwise known as latex allergy, are IgE-mediated reactions. These reactions occur within minutes of exposure to latex and can cause pruritus, urticaria, angioedema, and rhinoconjunctivitis. More severe symptoms are bronchospasm, hypotension, and anaphylaxis. Contact urticaria is most commonly reported with latex glove use. Facial and periorbital urticaria and angioedema can occur if latex gloves directly contact the face. Rhinitis, conjunctivitis, and asthma occur if latex proteins become airborne.
It is now known that latex allergens bind to cornstarch powder used in glove manufacturing and that significant levels of airborne latex proteins are found in medical and dental offices. Extensive studies performed at the Mayo Clinic demonstrate high levels of latex aeroallergens in operating rooms on days when many powdered latex gloves were used in the area, in contrast to minimal levels of airborne latex on weekend days and holidays when no gloves were used.6 This information has led to intervention policies to decrease levels of latex in operating rooms and hospitals.
Latex exposure to mucosal surfaces can be associated with systemic symptoms of hypotension, tachycardia, and bronchospasm, leading to anaphylaxis. Unfortunately, even limited mucosal exposure to latex has caused anaphylaxis; generalized reactions have occurred with toy balloons, urinary catheters, condoms, dental surgery, and rectal procedures.7
Another IgE-mediated reaction is the cross-reactivity between latex and several foods and fruits. Latex proteins share similar protein structures with other protective plant proteins found in fruits and foods. Latex-allergic persons have had oral symptoms of itching, swelling, and anaphylaxis with exposures to avocado, banana, and chestnuts. There have also been some reported reactions to potato, tomato, and kiwi.8 For this reason, latex-allergic patients should be questioned and informed about possible food reactions.
A pertinent history for symptoms related to latex exposures, tests to confirm the presence of IgE antibody, are necessary determine latex allergy. Provocative challenges can be completed if needed.
Essential in the workup of latex allergy is the clinical history. Clarification of symptoms that occur with exposure to latex gloves and with other common latex products, such as latex balloons or condoms, is critical. Onset of symptoms after latex exposure should be immediate, usually occurring within minutes to 1 hour. Patients commonly report symptoms of itching, redness, and hives with direct handling of latex products, itching of nose and eyes and wheezing with exposure to powdered latex gloves, and lip swelling when inflating latex balloons. Persons with histories of idiopathic urticaria, food allergy, and idiopathic anaphylaxis have been found to be latex allergic with hidden sources of latex exposure.
The two most common methods used to identify specific IgE antibody are the percutaneous (prick) skin test and radioallergosorbent test (RAST). Skin testing to identify latex-specific IgE antibody is convenient, sensitive, and fast. Current latex skin testing is problematic because there is no commercially available FDA-approved latex extract, and latex reagents in the United States vary in their preparation, potency, content, and reliability.
Three FDA-approved in vitro serologic tests for latex specific IgE antibody are the Immuno-CAP (Pharmacia-Upjohn, Uppsala, Sweden), AlaSTAT FEIA (Diagnostic Products Corp, Los Angeles, Calif.) and HYTEC-EIA (Hycor Biomedical, Garden Grove, Calif.). Immuno-CAP and AlaSTAT have comparable diagnostic sensitivity (76% and 73%) and specificity (96% and 97%), whereas HY-TEC has more sensitivity (93%), but lower specificity (73%).9
Allergists can perform an in vivo provocation test with latex gloves to establish latex allergy if the patient’s history and latex skin test or serologic test are discordant. The latex glove use test, when a latex glove is worn for 10 to 15 minutes and symptoms are then noted, is commonly used.10
Additional identification of food-specific IgE (either by skin test or RAST, if available) should be performed for persons who report allergic symptoms with fruits and vegetables that can cross-react with latex proteins.
The latex-allergic person must avoid natural rubber products to the best of his or her knowledge and ability, because there is no cure for latex allergy. It is appropriate to provide lists of latex-containing products as well as to advise about suitable alternative products. Complete latex avoidance is unreasonable to implement and may be unnecessary except for patients who demonstrate the most severe anaphylactic reactions. Reports of outcomes of latex-allergic health care workers show that nonpowdered latex gloves, low-allergen latex gloves, and nonlatex gloves allow some health care workers with latex allergy to continue to work with lessened clinical symptoms in latex-safe environments.11,12
Latex-allergic persons should wear medical-alert devices, carry self-injectable epinephrine if there have been prior systemic symptoms, and have latex allergy listed on medical and dental records.
Special considerations are needed for latex-allergic persons who have spina bifida, work in medical or dental settings and in the industrial rubber companies, and are undergoing surgery. Surgical operating rooms can be made latex-safe to decrease risk of anaphylaxis from latex exposure. Stringent latex avoidance measures are needed to prevent latex sensitization and worsening of clinical symptoms. All children with spina bifida are at high risk for latex allergy and should avoid latex in the home and hospital settings. Additional issues for workers with latex allergy include disability and workers’ compensation, development of latex-safe environments, and guidance in career options.
Medical management of latex allergy is identical to the treatment of other IgE-mediated reactions. Removal of the allergen should occur first, followed by administration of antihistamines and other medications (including corticosteroids) depending on the severity of symptoms. Epinephrine may be needed if there is progression to systemic reactions of anaphylaxis. Latex immunotherapy and omalizumab (Xolair) have also been administered in the treatment of latex allergy.13,14