Latex Allergy - Allergic Disorders

LATEX ALLERGY

Latex allergy, the allergic reaction to natural rubber proteins, has been implicated in rhinitis, conjunctivitis, contact dermatitis, urticaria, asthma, and anaphylaxis. Latex allergy and hypersensi-tivity were first reported in 1927 (Parslow et al., 2001). Although the prevalence of latex allergy is unknown, since 1989 the num-ber of cases of latex allergy has steadily increased (Parslow et al., 2001). This increase may be due to the widespread use of latex gloves with implementation of universal and now standard pre-cautions in response to the AIDS epidemic, changes in the man-ufacturing of gloves to speed the process to meet the increased demand for gloves, and greater awareness about latex allergy and its signs and symptoms.

Natural rubber latex is derived from the sap of the rubber tree (Hevea brasiliensis). The conversion of the liquid rubber latex into a finished product entails the addition of more than 200 chemi-cals. The proteins in the natural rubber latex (Hevea proteins) or the various chemicals that are used in the manufacturing process are thought to be the source of the allergic reactions. Not all ob-jects composed of latex have the same ability to stimulate an al-lergic response. For example, the antigenicity of latex gloves can differ widely depending on their manufacturing method.

Populations at risk include health care workers, patients with atopic allergies or multiple surgeries, people working in factories manufacturing latex products, females, and patients with spina bi-fida. Because more food handlers, hairdressers, auto mechanics, and police are now wearing latex gloves, they may also be at risk for latex allergy. It is estimated that 1% to 3% of the general population has an allergy to latex and that 10% to 17% of health care workers are sensitized. Patients are at risk for anaphylactic reactions due to con-tact with latex during medical treatments, especially surgical pro-cedures. About 19% of anaphylactic reactions associated with anesthesia are caused by allergy to latex (Brehler & Kütting, 2001).

Food that has been handled by individuals wearing latex gloves may stimulate an allergic response. Cross-reactions have been re-ported in people who are allergic to certain food products, such as kiwis, bananas, pineapples, passion fruits, avocados, and chestnuts.

Routes of exposure to latex products can be cutaneous, per-cutaneous, mucosal, parenteral, and aerosol. The most frequent source of exposure is cutaneous, which usually involves the wear-ing of natural latex gloves. The powder used to facilitate putting on latex gloves can become a carrier of latex proteins from the gloves; when the gloves are put on or removed, the particles be-come airborne and can be inhaled or can settle on skin, mucous membranes, or clothing. Mucosal exposure can occur from the use of latex condoms, catheters, airways, and nipples. Parenteral exposure can occur from intravenous lines or hemodialysis equip-ment. In addition to latex-derived medical devices, many house-hold items also contain latex. Examples of medical and household items containing latex and a list of alternative products are found in Table 53-5. It is estimated that over 40,000 medical devices and nonmedical products contain latex (Brehler & Kütting, 2001).

Clinical Manifestations

Several different types of reactions to latex are possible. Irritant con-tact dermatitis, a nonimmunologic response, may be due to me-chanical skin irritation or an alkaline pH associated with latex gloves. Common symptoms of irritant dermatitis include erythema and pruritus. These symptoms can be eliminated by changing glove brands or using powder-free gloves. Use of hand lotion before don-ning latex gloves may worsen the symptoms because lotions may leach latex proteins from the gloves, increasing skin exposure and the risk of developing true allergic reactions (Burt, 1998).

Delayed hypersensitivity to latex, a type IV allergic reaction mediated by T cells in the immune system, is localized to the area of exposure and is characterized by symptoms of contact der-matitis, including vesicular skin lesions, papules, pruritus, edema, erythema, and crusting and thickening of the skin. These symp-toms usually appear on the back of the hands. This reaction is thought to be due to chemicals that are used for manufacturing latex products. It is the most common allergic reaction to latex. Although not usually life-threatening, delayed hypersensitivity reactions often require major changes in the patient’s home and work environment to avoid further exposure.

Immediate hypersensitivity, a type I allergic reaction, is medi-ated by the IgE mast cell system. Symptoms can include rhinitis, conjunctivitis, asthma, and anaphylaxis. The term “latex allergy” is usually used to describe the type I reaction. Clinical manifesta-tions have a rapid onset and can include urticaria, wheezing, dys-pnea, laryngeal edema, bronchospasm, tachycardia, angioedema, hypotension, and cardiac arrest.

Localized itching, erythema, or local urticaria within minutes after exposure to latex are often the initial symptoms. Symptoms of subsequent reactions can include generalized urticaria, angio-edema, rhinitis, conjunctivitis, asthma, and anaphylactic shock minutes after dermal or mucosal exposure to latex. An increasing number of individuals allergic to latex experience severe reactions characterized by generalized urticaria, bronchospasm, and hypo-tension (Brehler & Kütting, 2001).

Diagnostic Testing

The diagnosis of latex allergy is based on the history and diag-nostic test results (Parslow et al., 2001). Sensitization is detected by skin testing, RAST, or ELISA. Skin tests have been unreliable because of variability in the techniques used; however, a new stan-dardized skin testing reagent is expected to be available in the near future. Skin tests should be done only by clinicians who have ex-pertise in their administration and interpretation and who have the necessary equipment available to treat local or systemic aller-gic reactions to the reagent (Hamilton & Adkinson, 1998). Nasal challenge and dipstick tests may be useful in the future as screen-ing tests for latex allergy.

Medical Management

The best treatment available for latex allergy is the avoidance of latex products, but this is often difficult because of the widespread use of latex-based products. Patients who have experienced an anaphylactic reaction to latex should be instructed to wear med-ical identification. Antihistamines and an emergency kit con-taining epinephrine should be provided to these patients, along with instructions about emergency management of latex allergy symptoms. Patients should be counseled to notify all health care workers as well as local paramedic and ambulance companies about their allergy. Warning labels can be attached to car win-dows to alert police and paramedics about the driver’s or passen-ger’s latex allergy in case of a motor vehicle crash. Individuals with latex allergy should be provided with a list of alternative products and referred to local support groups; they are also urged to carry their own supply of nonlatex gloves.

People with type I latex sensitivity may be unable to continue to work if a latex-free environment is not possible. This may occur with surgeons, dentists, operating room personnel, or in-tensive care nurses. Occupational implications for employees with type IV latex sensitivity are usually easier to manage by changing to nonlatex gloves and avoiding direct contact with latex-based medical equipment. Although latex-specific immuno-therapy has been reported, this method of treatment remains ex-perimental (Brehler & Kütting, 2001).

Nursing Management

The nurse can assume a pivotal role in the management of both patients and staff with latex allergies. All patients should be asked about latex allergy, although special attention should be given to those at particularly high risk (eg, patients with spina bifida, patients who have undergone multiple surgical procedures). Every time an invasive procedure must be performed, the nurse should consider the possibility of latex allergies. Nurses working in op-erating rooms, intensive care units, short procedure units, and emergency departments need to pay particular attention to latex allergy.

Although the type I reaction is the most significant of the re-actions to latex, care must be taken in the presence of irritant contact dermatitis and delayed hypersensitivity reaction to avoid further exposure of the individual to latex. Patients with latex al-lergy are advised to notify their health care providers and to wear a medical information bracelet. Patients must become knowl-edgeable about what products contain latex and what products are safe, nonlatex alternatives. They must also become knowl-edgeable about signs and symptoms of latex allergy and emer-gency treatment and self-injection of epinephrine in case of allergic reaction.

Nurses can be instrumental in establishing and participating in multidisciplinary committees to address latex allergy and to promote a latex-free environment. Latex allergy protocols and ed-ucation of staff about latex allergy and precautions are important strategies to reduce this growing problem and to ensure assess-ment and prompt treatment of affected individuals.