Latex is the milky sap harvested from the commercial rubber tree grown in the rain forest of Africa and South East Asia, and is a complex intracellular product. Latex is widely used as it possesses a variety of desirable qualities, including strength, flexibility, tear resistance, the ability to self seal small punctures and barrier integrity (Evangelisto, 1997). The cloudy white liquid latex is collected ‘tapping’ the tree. It then undergoes a complex coagulation process, involving the addition of sulphur and organic chemicals e.g. accelerators. This process provides the strength, elasticity and dimensional stability characteristic of many rubber products, which make it ideally suited for use in the health care arena. Therefore natural rubber latex is composed of natural proteins and added chemicals, some of which will be removed during washing procedures conducted during the latter stages of production.

An allergy is a state of abnormal and individual hypersensitivity acquired through exposure to a particular allergen. An allergen is a substance or protein that is capable of producing an allergy or specific hypersensitivity (Collins, 1986).

A latex allergy is the reaction of an individual to one of the proteins found in the milky sap, of which there are 240. At least 10 of these proteins have been implicated as allergens (Evangelisto, 1997).

The reaction occurs when an item containing latex comes into contact with any part of the body, directly or via aerosol. The allergic reaction that results can manifest itself in many ways. This immune response is marked by the release of antibodies or immunoglobulins. Though many are released, two particular antibodies produced elicit the greatest response. The immunoglobulins thought responsible are Immunoglobulin G and Immunoglobulin E. Once produced these immunoglobulins continue to circulate in the blood (Furay, 1991).

Although the first report of an adverse reaction to latex dates back to 1927, the first cases of latex allergy in North America were published in 1989. IT was not until the Center for Disease Control and Prevention, Atlanta issued guidelines for Universal Precautions in 1987, in response to the AIDS epidemic, that glove use increased 8 fold in 1 year. These guidelines instructed health care workers to wear gloves for almost the entire working day to prevent infection. This increased use may have lead to an increased sensitisation in people who spend a great deal of time around latex products as continued exposure increases sensitivity.

Turjanma (1993) points out that the prevalence and incidence of natural rubber latex allergy still remains unquantified. However, one estimate suggests that the incidence in the general population is less than 1%, but may be higher within certain risk groups. For groups at risk see Table 1.

In the USA, as a result of the recent accelerated demand for gloves, many glove manufacturers, inexperienced in the production of latex products for health care use, expanded production rapidly and may have distributed gloves with high levels of latex allergens. Some of these products were not subject to quality assurance procedures appropriate for medical devices. These firms may have shortened the washing or leaching procedure which drains away free standing latex proteins, in order to satisfy demands (Evangelisto, 1997). As a measure of the increasing demand, between 1987 and 1989 the Malaysian Rubber Development Board received over 400 applications to form glove companies, where previously only 25 had existed (Medical Devices Agency, 1996).

There are significant costs associated with a latex allergy in the Health care institute. These can be divided in to costs for:

• The Health Care Worker
• The Institution
• The Manufacturers

For the Health Care Worker the costs incurred could range from a few days of sick leave to potentially, a decreased earning capacity. Weinert (1998) points out that some institutions have been successful in relocating staff members internally to areas where antigen content is low. Unfortunately, seriously sensitised workers cannot be relocated within some institutions because the ambient content is high enough to cause a reaction. These highly sensitised individuals often require job changes that involve learning new skills. Often, career changes mean Health Care Workers are working at a lower income level.

For the Institution, costs are high. Institutions must bear the cost of manufacturers’ lack of purification or washing processes, and legal recourse may be a possibility. Costs include personnel, glove replacement, consultants and remediation costs.

Personnel costs cover workers compensation, disability allowance, retraining and legal costs involved in deciding on amount payable.

Glove replacement means new low protein gloves have to be found, tested and approved by all who need to use them. Unsuitable gloves need to be withdrawn and possibly returned to manufacturer for credit or to be discarded. By standardising on fewer manufacturers and ensuring gloves are used correctly it may be possible to save money long term.

Consultants’ costs involve employing an industrial hygiene consultant. They help in designing latex allergy management programs, training, identifying exposure levels to antigen, and developing site specific procedures for remediation.

Remediation contractors are assigned to clean the environment. This means cleaning the physical space and accessory support areas (Weinert, 1998).

The Manufacturers must remove latex proteins from the finished latex products to prevent systemic allergic response. The cost to purify and centrifuge is significant because each washing and subsequent centrifuging reduces the amount of latex for product manufacture (Weinert, 1998). Some of the costs from research and development will be passed on in higher prices to the consumer.

Patients and staff need to be protected from unnecessary latex exposure. A hospital can help to prevent latex reactions by taking the following steps:

• Establish a multidisciplinary committee to develop policies and procedures
• Identify products containing latex
• Identify latex sensitive patients and employees, and others at high risk of developing latex sensitivity
• Implement precautions
• Educate personnel about the risks of latex, educate latex sensitive patients and employees, and about the preventive measures to be followed
• Review quality assurance data on latex sensitive patients’ hospital stay, and monitor documented employee reactions, to assess and continually improve precautionary procedures.

Due to the wide variety of products containing latex, and the many concerns about latex, the committee, Young, Meyers, McCulloch and Brown (1992) says should begins as a facility wide approach. To develop effective strategies, a multidisciplinary committee should consist of representatives from departments and disciplines involved directly and indirectly in patient care (Young et al., 1992). This group should be educated about latex allergy and must strongly advocate changing to a latex save environment and thus, must fully understand the risks of latex exposure. This group should address educational issues, patient care practices, and occupational health guidelines. The resulting procedures must be disseminated and adhered to carefully to avoid inadvertently exposing patients to latex. Young et all., (1992) advises that the best approach may be to develop a universal institutional policies and procedures that encompass all areas of practice, with an addendum to include individualised department specific guidelines.

The most effective way to reduce adverse reactions to latex is to avoid latex exposure both in the healthcare setting and in the home. Since there are so many potential sources of latex, an institution cannot provide a totally latex free environment for patients or employees. Still, many steps can be taken to provide a safer environment for the patients and employees at risk. The latex content of products and packaging materials must be identified. Manufacturers can be contacted for product specific information. However, many difficulties may be encountered. Terminology may vary among manufacturers, and there may be insufficient information. Young et al., (1992) state that written documentation of products content from the manufacturers is always recommended. Some producers may give answers provided by their legal department rather than state the actual latex content, as products change and contents may vary with the lot number. The latex manufacturing process will become more carefully regulated and controlled.

Since January 1^st 1995, a manufacturers must comply with the Community European (CE) Directives to enable this sale of medical devices in the member countries of the European Community. As this market is about as large as the US market, many medical device manufacturers, including surgical glove producers, have sought the CE mark, which is a certification of compliance with the CE Directives (Witmeyer & Sellers 1997). On 30^th September 1997, The Food and Drug Administration (FDA) of the United States issued a final ruling requiring that all medical devices containing natural rubber latex must carry a warning statement. Manufacturers had until 30^th September 1998 to comply.

Each health care institution should develop its won definition of latex sensitive. Specifically, it should decide whether patients will be described as latex sensitive only if they have documented reactions, or also when they fall into a high risk group. Once the definition is determined, procedures can be established for identifying patients who require latex precautions and for communicating these requirements to all staff caring for these patients.

Present as a dryness or cracking of the skin in areas exposed to latex gloves. This condition tends to be chronic although it improves during periods when the glove is not worn, it is a non-allergic reaction. It is important to point out that thought latex can cause allergic contact dermatitis (Furay, 1991), many other factors such as chemicals associated with gloves, handwashing detergents and scrubbing technique can also cause contact dermatitis (Seymour, 19995).

Type 4 is a delayed response. It occurs 6 to 48 hours after contact and includes erythema, pruritus, oedema, cracking of the skin, vesicle formation and red swollen rashes that appear only on skin areas that touched latex. This can become a chronic condition with continued exposure, with dryness, scaling, fissuring and thickening of the skin (Thompson, 1996). This is predominantly caused by an allergy to the residues of accelerating agents used in the manufacturing process of gloves.

Type 1 is an immediate reaction that happens within minutes to 2 hours, depending on route of absorption and dose of allergen. This reaction is predominantly a response to the natural protein residue found in natural rubber latex. This involves immunoglobulin E which binds to mast cells and basophils which cause them to degranulate (Young et all., 1992). This produces mediators including histamine and anarchidionic acid which in turn causes the release of prostaglandin and leukotrines (Furay, 1991). The net result is local and systemic changes. There is vasodilatation, smooth muscle contraction (bronchospasm) and increased vascular permeability. It may present with contact or generalised urticaria, respiratory symptoms, anaphylactic shock and angioedema. The awake patient may feel light headed and experience laryngeal oedema, and syncope. Left untreated the condition may progress to vascular collapse, cardiac dysrythmia and death (Thompson, 1996). For treatment see Table 3.

According to Burt (1998), as of June 1996, 28 latex related deaths had been reported to the Food and Drug Administration (FDA).

Whenever latex sensitisation is suspected, diagnostic testing should be encouraged in order to identify the allergen. Appropriate advice can be provided on allergy avoidance and alleviation of symptoms. A thorough history should be made with particular note to any previous reactions and their possible cause. A pre-admission questionnaire could be completed in order to determine if further testing or diagnosis is needed (see Table 4). Blood and skin tests, preferably carried out by a specialist in latex allergy, may be performed but no test is 100% accurate.

There are several ways of diagnosing latex allergy, these include:

A drop of latex exudate is placed on the skin and a lancet is used to puncture the skin at the site of exudate. A drop of normal saline is also placed on the skin and similarly the skin is punctured as a control. The reaction from both is compared (Young et al., 1992).

This is the wearing of one latex and one vinyl glove for a period of time, the hands are then compared (Turjanmaa, 1987). It has been recommended that only one finger of a glove be used initially, in order to minimise the risk to the highly sensitised individuals. The inner surface of the glove or the hand of the subject are dampened prior to administration of the allergen. Only the source material is identified, not the specific allergen.

This can be used to identify specific contact antigens involved in delayed reactions, causing allergic dermatitis. It involves a two day occlusive application of the test material, when patches of glove containing various allergenic rubber chemical additives are taped to a persons’ back. The skin reaction beneath each patch is checked at 48 hours and again at 96 hours to determine which additives cause sensitivity.

The advantage of diagnostic methods such as RAST (radioallergosorbent) testing is that the reaction and determination is made in vitro rather than on the surface of the subject’s skin, so it poses no risk of triggering anaphylaxis. The reaction between patients’ serum and test material identifies latex specific IgE. However, these tests are expensive and sensitivity is such that allergic individuals may go undetected if the tests are used in isolation. Once it is determined that latex precautions are indicated, this information must be communicated to all health care workers who will be caring or preparing products for the patient. This may be done by flagging the patient’s computer record, placing an allergy sticker on the patient’s chart, identifying the patient with a wristband, and displaying a sign in the patient’s room.

• Environmental

Several precautions can be taken to prevent latex from touching a latex sensitive person’s skin, mucous membranes, or internal organs. Latex containing products in the patient’s room should be replaced whenever possible. Many safe alternatives are becoming readily available, although these are often more expensive. Any remaining products should be covered e.g. by tying stockinette around all electrical cords and the rubber tubes on a blood pressure cuff, and using a latex free tape to secure ends. A cart of latex free materials cans be placed in the patient’s room (see Table 5).

• Medications

Additives should not be injected through latex ports on intravenous bags or bottles. Solutions should be added through the non latex tubing port after the rubber cap has been removed. Melton (1992) states that the risk of exposure from syringes with rubber stopper is not clear. One study showed a skin reaction in some, but not all, of 12 latex sensitive patients injected with extracts made from syringe stoppers.

• Products

Some gloves are powdered, and the latex allergens adhere to this powder. This then becomes a transport medium for the latex proteins, increasing the exposure as they become airborn (Evangelisto, 1997). The allergens may then be inhaled or float to inoculate surgical tissue, contaminate suture material, instruments, drapes or swabs. Hands sweat inside latex gloves making the latex proteins soluble, which can then be absorbed through the skin, sensitising the wearer further. Gloves are not the only culprit, but due to their widespread use, they are the most prevalent medical device capable of causing or exacerbating latex allergy (Evangelisto, 1997). For other commonly used health care products containing latex, see Table 6.

We know avoidance is the key to preventing latex allergy, we should therefore reduce the amount of powdered gloves in use. As totally eliminating latex gloves may not be feasible we should purchase gloves which are known to have low levels of allergens. If possible, a person with a latex sensitivity should wear unpowdered synthetic gloves, with no natural rubber. Coworkers of allergic individuals should also wear nonlatex gloves, or at the very least, powder free, low protein gloves (Evangelisto, 1997).

• Procedures

All patients with a latex allergy should be scheduled as the first case of the day, as this allows time for thorough cleaning of the room, removal of latex containing products, and reduction of aerosolised proteins.

Young at al., (1992) states that education both formal and informal, is the key to success when introducing a new policy. Before implementing a change in practice, all staff members must learn about the dangers of aerosolised latex allergens from latex glove powder and the differences between low allergen powder free latex gloves and high allergen powdered latex gloves (see Table 7). Along with cardiopulmonary resuscitation (CPR) and fire drill updates, latex allergy review could be part of the mandatory yearly requirements for healthcare workers, ensuring that all staff members remain up to date in this area. Young et al., (1992) mentions that patients and families also need education about latex allergy. An information package should be developed to provide them with valid highlights, and product contents for the home and community. Patients should be alerted to the importance of limiting exposure to latex products by using other alternatives. Health care workers can help the patient to find alternative products and methods e.g. wrapping products to create a barrier and minimise exposure. Latex allergy patients should also be warned that some foods have caused cross reactions in some patients (see Table 5). Patients should be encouraged to wear medical alert bracelets and to carry latex allergy information in their wallets, as well as latex free gloves.

The Oregon Nurses Association drafted the first State Legislation in the United States that would have banned powdered gloves. While the bill was not passed, their efforts did succeed in educating the general public on the hazards of latex (Peterson, 1997).

As with most issues, the main problem is the continuing education of both health care workers and the general public. We need to be able to demonstrate an accurate and cost effective testing mechanism, which can be widely available. This testing may explain previous undiagnosed episodes of concern during a hospital admission.

It may not be long before employers ask about latex sensitivity when interviewing prospective employees, whether these questions are to be interpreted as some form of job discrimination is yet to be seen. Beezhold and Sussman (1997) state that researchers agree that the lower the protein value, the lower the potential for that product to cause an allergic reaction. Researchers do not know what level of protein is safe and what level of protein can be tolerated on a glove without causing sensitisation. On a positive note, a health care facility that has switched to low protein, powder free gloves and is changing to suppliers that produce low latex protein devices, has an excellent marketing tool. To be able to boast of a latex safe workplace can be a key recruitment tool. Powder free, low protein gloves are expensive, but so is latex allergy. Balancing glove cost with employee and client safety is crucial (Johns, 1998).

REFERENCES

Adkins, D. (1997). Latex products in the hospital environment. Journal of Emergency Nursing, 23(2), 135-141.

Australian Therapeutic Device Bulletin (1997). 34, 3/97, 3.

Burt, S. (1998). What you need to know about latex allergy. Nursing, 98, 33-40.

Beezhold, D., & Sussman, G., (1997) Determining the allergenic potential of latex gloves. Surgical Services Management, Vol. 2 (2) February 1997.

Collins Paperback English Dictionary, (1986). William Collins & Sons. Ltd.

Daly, S., Fontana, D. & Senini, L. (1997). Latex Allergy a preoperative perspective. Monash Medical Centre, July.

Evangelisto, M. (1997). Latex allergy: the downside of standard precautions. Today’s Surgical Nurse, September/October, 28-33.

Furay, M. (1991). Hand dermatitis: the role of gloves. AORN Journal, 54(3), 451-465.

Great Ormond Street Hospital for Sick Children (1997). Drug administration guidelines. Latex Allergy Protocol, 13-14.

Johns, C. (1998). A call to action. Surgical Services Management, 4(3), 41-44.