See related patient information handout on latex allergy , written by the author of this article.

Natural latex from the rubber tree Hevea brasiliensis is an allergen in persons with significant cumulative latex exposure, such as those in the health care and rubber industries, as well as those undergoing repeated surgeries, especially if they undergo surgeries early in life. Symptoms of latex allergy may progress rapidly and unpredictably to anaphylaxis. The prevalence of latex allergy has increased as the use of rubber gloves in health care settings has increased. Airborne latex particles that adhere to the cornstarch used to powder gloves are a significant cause of respiratory symptoms and a source of sensitization. Once an individual has become sensitized, he or she may experience allergic symptoms when exposed to any product containing latex. Diagnosis is made initially by the history. Latex-specific IgE testing and skin prick testing may confirm the suspicion. The most effective strategy in the treatment of latex allergy is avoidance; however, there is a large group of sensitized people who have not been identified and who do not recognize that their symptoms are caused by latex allergy. Physicians caring for latex-sensitive persons must act as their advocates in building awareness of the problem and developing protocols for their safe care. Latex-sensitized persons should be educated about the latex content of common objects.

Natural rubber latex has been in widespread use for over a century. Reports of immediate hypersensitivity to latex have increased dramatically since the first case was reported (in English) in 1979.1 Sixteen deaths occurred in association with the use of a latex barium enema tip, leading to the recall of the device in 1991 by the U.S. Food and Drug Administration (FDA)2 and an increase in awareness of the risk of a life-threatening type I allergy associated with natural latex devices. Ten to 17 percent of health care workers have already become sensitized, and over 2 percent have occupational asthma as a result of latex exposure.3

Other persons at high risk of sensitization include those with cumulatively prolonged exposure to latex. Among those who have undergone repeated surgeries, particularly early in life—especially those with myelomeningocele (spina bifida) or urogenital abnormalities—the prevalence of latex allergy may be greater than 60 percent (Table 1). Workers in the latex manufacturing industry are also at risk, with one glove manufacturing plant reporting a 3.7 percent prevalence of occupational asthma caused by latex allergy among its employees, based on positive results of skin prick testing and spirometric data.4 Among workers at a latex doll manufacturing plant, the prevalence of latex sensitization was also shown to be significant.5

View/Print Table TABLE 1 Risk Groups for Latex Allergy* Health care workers Rubber industry workers Persons witih spina bifida or urogenital abnormalities Persons who have undergone repeated or prolonged surgeries or mucous membrane exposure to latex devices, especially early in life Persons with an atopic history or history of food allergy (cross-reacting proteins, especially in banana, avocado, passion fruit, chestnut, kiwi fruit, melon, tomato, celery) TABLE 1 Risk Groups for Latex Allergy* Health care workers Rubber industry workers Persons witih spina bifida or urogenital abnormalities Persons who have undergone repeated or prolonged surgeries or mucous membrane exposure to latex devices, especially early in life Persons with an atopic history or history of food allergy (cross-reacting proteins, especially in banana, avocado, passion fruit, chestnut, kiwi fruit, melon, tomato, celery)

While studies repeatedly uncover high prevalence rates, the nonspecific nature of symptoms and lack of knowledge about latex allergy result in missed diagnosis in many sensitized persons who are at risk of progression to serious allergic reactions.

Since 1985, the establishment of policies of “universal precautions” and the increased barrier requirements resulting from the epidemic of human immunodeficiency virus infection and acquired immunodeficiency syndrome have resulted in an exponential increase in the use of latex gloves. In 1987, 1 billion latex gloves were imported into the United States; in 1988, 8 billion gloves were imported.6 The use of latex condoms has also increased. It appears that the increase in total exposure to latex and variations in manufacturing have led to a true increase in the number of persons with latex sensitivity.

Illustrative Case Jump to section + Abstract

Illustrative Case

Latex Origins and Latex Products

Allergic Reactions

Diagnosis

Management

References A 37-year-old woman reported that during college, she had experienced three bouts of urticaria of unknown origin involving lip mucosa and skin. She experienced similar symptoms following repair of a fractured femur, but these symptoms were attributed to an antibiotic reaction. While the patient was in medical school, she noted occasional localized hives following use of latex gloves and, despite switching to “hypoallergenic” latex gloves, she continued to have hives every few months. Increased urticaria, at times generalized, continued to occur. During the patient's second pregnancy, a vaginal examination with membrane stripping was performed by a physician wearing latex gloves. Within 30 minutes of this procedure, the patient had an anaphylactic reaction that necessitated hospitalization and resuscitation. One week later, a nonelective cesarean delivery necessitated multilevel consultation to create a latex-free environment for her safe care. At five-year follow-up, the patient has been forced to leave hospital practice because of symptoms of asthma. She now works in a clinic where latex is not used, but she continues to have hives whenever staff (wearing latex gloves) from an adjacent dental clinic are in proximity. She reports a history of atopic illness and has developed food allergies to avocado and melon.

Latex Origins and Latex Products Jump to section + Abstract

Illustrative Case

Latex Origins and Latex Products

Allergic Reactions

Diagnosis

Management

References Latex products are derived from the latex sap of commercially grown rubber trees, Hevea brasiliensis. The sap is extracted and heated while chemical preservatives, primarily ammonia, are added to enhance the rubber's structural qualities. Latex contains low-molecular-weight soluble proteins, which are the cause of IgE-mediated allergic reactions. At least 10 different proteins have been implicated.7 Added accelerators and antioxidants may also be significant mediators of type IV or allergic contact dermatitis, and may cause or exacerbate irritant contact dermatitis. Latex products are made either by pouring the rubber into molds or by forming a coating in a dipped process, as is done with gloves, balloons and condoms. Dipped, or very soft, rubber products appear to have the highest content of latex proteins and, therefore, have the greatest allergenic potential. Cornstarch powder is applied to latex gloves during the manufacturing process to prevent stickiness and give the gloves a smooth feel. Latex protein particles have been shown to adhere to the surface of these cornstarch particles and to aerosolize on removal of the gloves.8 High-exposure areas, such as operating rooms and labor and delivery suites where powdered latex gloves are used, contain sufficiently elevated concentrations of aerosolized latex to produce significant symptoms in sensitized persons. Based on manufacturer, lot number and type of gloves, considerable variation exists in the antigenicity of latex gloves and the potential for aerosolization of latex by the “snap” of gloves on removal.9,10 Latex proteins are water soluble. Manufacturing processes including washing, chlorination and other treatments can reduce the burden of latex protein antigen. Low protein, powder-free gloves have minimal potential for sensitization in those who have not yet become sensitized to latex.

Allergic Reactions Jump to section + Abstract

Illustrative Case

Latex Origins and Latex Products

Allergic Reactions

Diagnosis

Management

References Latex allergy can give rise to a broad range of symptoms (Table 2). Glove wearers may experience a type IV, or delayed hypersensitivity, contact dermatitis that ranges from non-specific pruritus to eczematous, red, weepy skin. These symptoms and the irritant contact dermatitis are caused by the accelerators and chemicals used in glove manufacture and not by the latex itself. Avoidance of latex gloves or the use of glove liners, and attention to hand care and minimizing occlusion, are often sufficient to contain these symptoms. View/Print Table TABLE 2 Symptoms of Latex Allergy Irritant contact dermatitis (nonimmune) Gradual onset, over days, caused by hand washing, occlusion, antiseptics and glove chemicals; symptoms include redness, cracks, fissures, scaling Allergic contact dermatitis, or type IV (delayed hypersensitivity) Onset six to 48 hours after contact, caused by chemicals; symptoms include erythema, vesicles, papules, pruritus, blisters, crusting Immediate hypersensitivity, or type I Onset within minutes, very rarely longer than two hours, caused by latex; symptoms include local and generalized urticaria, feeling of faintness, feeling of impending doom, angioedema, nausea, vomiting, abdominal cramps, rhinoconjunctivitis, bronchospasm, anaphylactic shock TABLE 2 Symptoms of Latex Allergy Irritant contact dermatitis (nonimmune) Gradual onset, over days, caused by hand washing, occlusion, antiseptics and glove chemicals; symptoms include redness, cracks, fissures, scaling Allergic contact dermatitis, or type IV (delayed hypersensitivity) Onset six to 48 hours after contact, caused by chemicals; symptoms include erythema, vesicles, papules, pruritus, blisters, crusting Immediate hypersensitivity, or type I Onset within minutes, very rarely longer than two hours, caused by latex; symptoms include local and generalized urticaria, feeling of faintness, feeling of impending doom, angioedema, nausea, vomiting, abdominal cramps, rhinoconjunctivitis, bronchospasm, anaphylactic shock Anaphylactic reactions to latex have been reported in persons who had previously only experienced irritant or allergic contact dermatitis. One theory is that underlying dermatitis breaches the skin's protective barrier, facilitating increased latex protein absorption and increasing the likelihood that the person will become sensitized to latex.8 Contact dermatitis may also be caused by a wide range of chemicals used in glove manufacturing; in particular, the accelerators. Direct skin contact with latex may cause a type I, or immediate hypersensitivity, IgE-mediated reaction within 30 to 60 minutes of exposure. Urticaria may be local or generalized, and the spectrum of progression is notably unpredictable—some persons have experienced anaphylactic reactions after having minimal or no previous symptoms. It is possible to have used latex gloves for years and to suddenly have a progression to systemic symptoms. Studies indicate that over 50 percent of persons who are sensitive to latex have a history of some type of atopic illness.11 It has been shown that among atopic health care workers, one in four have a positive skin prick test to latex. Since only 50 percent of these persons were clinically symptomatic, the clinical implications for the other 50 percent remain uncertain.12 Curiously, certain fruits such as bananas, chestnuts, kiwi fruit, avocado and tomato13 show cross-reactivity, perhaps because of resemblance to a latex protein component. These foods have been responsible for anaphylactic reactions in latex-sensitive persons, while many other foods, including figs, apples, celery, melons, potatoes, papayas and pitted fruits, such as cherries and peaches, have caused progressive symptoms beginning with oral itching.14 Persons with a history of reactions to these foods are at increased risk of developing latex allergy, and those who are sensitive to latex should avoid foods to which they have had previous reactions. While food cross-reactions remain an evolving area of knowledge, it is clear that the elimination of all of these foods would cause significant dietary restriction and is therefore not recommended categorically for latex-allergic persons.

Diagnosis Jump to section + Abstract

Illustrative Case

Latex Origins and Latex Products

Allergic Reactions

Diagnosis

Management

References Diagnosis of latex allergy is made by the history and by immunologic testing; a thorough medical history is the cornerstone of diagnosis. The patient should be asked about his or her occupation, and other factors for high risk should be explored (Table 3). Also, the history should determine whether previous reactions have occurred in an occupational or other setting and, if so, what type of reactions occurred. Reactivity to foods, symptoms following use of a rubber condom or diaphragm, or symptoms associated with pelvic examination should raise the suspicion of latex sensitivity (Table 4). View/Print Table TABLE 3 Screening Questionnaire to Determine Latex Sensitivity Allergies Do you have a history of hay fever, asthma, eczema, allergies or rashes? Are you allergic to any foods, especially bananas, avocados, kiwi or chestnuts? Do you experience rash, oral itching, swelling or wheezing when exposed to these foods? Occupation Are you exposed to any products that contain latex, including gloves, at work? Have you ever had an allergic reaction to something in your work environment? If you have had a rash on your hands after wearing latex gloves, how long after putting on the gloves did the rash develop? What did the rash look like? Hidden reactions to latex Have you ever had swelling, itching, hives, shortness of breath, cough or other allergic symptoms during or after blowing up a balloon, undergoing a dental procedure, using condoms or diaphragms, or following a vaginal or rectal examination? Have you ever had an allergic reaction of unknown cause, especially during a medical or dental procedure? Surgical history Have you ever had surgery? If so, what kind? Do you have spina bifida or any urinary tract problem requiring surgery or catheterizations? TABLE 3 Screening Questionnaire to Determine Latex Sensitivity Allergies Do you have a history of hay fever, asthma, eczema, allergies or rashes? Are you allergic to any foods, especially bananas, avocados, kiwi or chestnuts? Do you experience rash, oral itching, swelling or wheezing when exposed to these foods? Occupation Are you exposed to any products that contain latex, including gloves, at work? Have you ever had an allergic reaction to something in your work environment? If you have had a rash on your hands after wearing latex gloves, how long after putting on the gloves did the rash develop? What did the rash look like? Hidden reactions to latex Have you ever had swelling, itching, hives, shortness of breath, cough or other allergic symptoms during or after blowing up a balloon, undergoing a dental procedure, using condoms or diaphragms, or following a vaginal or rectal examination? Have you ever had an allergic reaction of unknown cause, especially during a medical or dental procedure? Surgical history Have you ever had surgery? If so, what kind? Do you have spina bifida or any urinary tract problem requiring surgery or catheterizations? View/Print Table TABLE 4 Sources of Possible Latex Exposure Medical Gloves Urinary catheters Face masks Tourniquets Adhesive tape Bandages Wound drains Injection ports Electrode pads Rubber syringe stoppers and medication vial stoppers Bulb syringes Mattresses on stretchers Dental devices Stethoscope and blood pressure cuff tubing Ambu bags PCA syringes Household Balloons Condoms and diaphragms Rubber bands Shoe soles Erasers Toys Sports equipment Carpet backing Feeding nipples and pacifiers Clothing, including elastic on underwear Food handled with powdered latex gloves Handles on racquets, tools Diapers, sanitary and incontinence pads Computer mouse pads Buttons on electronic equipment TABLE 4 Sources of Possible Latex Exposure Medical Gloves Urinary catheters Face masks Tourniquets Adhesive tape Bandages Wound drains Injection ports Electrode pads Rubber syringe stoppers and medication vial stoppers Bulb syringes Mattresses on stretchers Dental devices Stethoscope and blood pressure cuff tubing Ambu bags PCA syringes Household Balloons Condoms and diaphragms Rubber bands Shoe soles Erasers Toys Sports equipment Carpet backing Feeding nipples and pacifiers Clothing, including elastic on underwear Food handled with powdered latex gloves Handles on racquets, tools Diapers, sanitary and incontinence pads Computer mouse pads Buttons on electronic equipment Frequently, either because of a lack of awareness of latex allergy and/or because of a concomitant history of atopic illness, sensitized persons do not attribute their respiratory symptoms of rhinoconjunctivitis or bronchospasm to latex exposure. For this reason, eliciting a suspicious history before elective surgery or other major latex exposure is of utmost importance. However, none of the patients whose deaths were attributed to anaphylaxis caused by latex exposure had any known risk factors other than atopic illness, illustrating that the above precautions may be insufficient.15 Standardized extracts for skin prick testing are not available in the United States. Therefore, because such testing may cause anaphylaxis, it should only be conducted by centers with experience in preparing extracts. FDA-approved in vitro tests to measure latex-specific IgE are available (Pharmacia CAP, Pharmacia-UpJohn Diagnostics Inc, Kalamazoo, Mich.; AlaSTAT, Diagnostic Products Corp., Los Angeles, Calif.).16 The low specificity of these tests, which have a false-negative rate of at least 20 percent and, thus, unclear positive predictive value, limits clinical usefulness. Negative serologic testing with a strongly positive history would suggest the value of skin prick testing to confirm the diagnosis.