With the advent of the universal precautions against bloodborne infections which dictate the use of gloves whenever HCWs are exposed to patients or materials that might be infected with hepatitis B or HIV, the frequency and severity of allergic reactions to natural rubber latex (NRL) have zoomed upward. For example, the Department of Dermatology at the Erlangen-Nuremberg University in Germany reported a 12-fold increase in the number of patients with latex allergy between 1989 and 1995. More serious systemic manifestations increased from 10.7% in 1989 to 44% in 1994-1995 (Hesse et al. 1996).
It seems ironic that so much difficulty is attributable to rubber gloves when they were intended to protect the hands of nurses and other HCWs when they were originally introduced toward the end of the nineteenth century. This was the era of antiseptic surgery in which instruments and operative sites were bathed in caustic solutions of carbolic acid and bichloride of mercury. These not only killed germs but they also macerated the hands of the surgical team. According to what has become a romantic legend, William Stewart Halsted, one of the surgical “giants” of the time who is credited with a host of contributions to the techniques of surgery, is said to have “invented” rubber gloves around 1890 to make it more pleasant to hold hands with Caroline Hampton, his scrub nurse, whom he later married (Townsend 1994). Although Halsted may be credited with introducing and popularizing the use of rubber surgical gloves in the United States, many others had a hand in it, according to Miller (1982) who cited a report of their use in the United Kingdom published a half century earlier (Acton 1848).
Latex Allergy
Allergy to NRL is succinctly described by Taylor and Leow (see the article “Rubber contact dermatitis and latex allergy” in the chapter Rubber industry) as “an immunoglobulin E-mediated, immediate, Type I allergic reaction, most always due to NRL proteins present in medical and non-medical latex devices. The spectrum of clinical signs ranges from contact urticaria, generalized urticaria, allergic rhinitis, allergic conjunctivitis, angioedema (severe swelling) and asthma (wheezing) to anaphylaxis (severe, life-threatening allergic reaction)”. Symptoms may result from direct contact of normal or inflamed skin with gloves or other latex-containing materials or indirectly by mucosal contact with or inhalation of aerosolized NRL proteins or talcum powder particles to which NRL proteins have adhered. Such indirect contact can cause a Type IV reaction to the rubber accelerators. (Approximately 80% of “latex glove allergy” is actually a Type IV reaction to the accelerators.) The diagnosis is confirmed by patch, prick, scratch or other skin sensitivity tests or by serological studies for the immune globulin. In some individuals, the latex allergy is associated with allergy to certain foods (e.g., banana, chestnuts, avocado, kiwi and papaya).
While most common among health care workers, latex allergy is also found among employees in rubber manufacturing plants, other workers who habitually use rubber gloves (e.g., greenhouse workers (Carillo et al. 1995)) and in patients with a history of multiple surgical procedures (e.g., spina bifida, congenital urogenital abnormalities, etc.) (Blaycock 1995). Cases of allergic reactions after the use of latex condoms have been reported (Jonasson, Holm and Leegard 1993), and in one case, a potential reaction was averted by eliciting a history of an allergic reaction to a rubber swimming cap (Burke, Wilson and McCord 1995). Reactions have occurred in sensitive patients when hypodermic needles used to prepare doses of parenteral medications picked up NRL protein as they were pushed through the rubber caps on the vials.
According to a recent study of 63 patients with NRL allergy, it took an average of 5 years of working with latex products for the first symptoms, usually a contact urticaria, to develop. Some also had rhinitis or dyspnoea. It took, on average, an additional 2 years for the appearance of lower respiratory tract symptoms (Allmeers et al. 1996).
Frequency of latex allergy
To determine the frequency of NRL allergy, allergy tests were performed on 224 employees at the University of Cincinnati College of Medicine, including nurses, laboratory technicians, physicians, respiratory therapists, housekeeping and clerical workers (Yassin et al. 1994). Of these, 38 (17%) tested positive to latex extracts; the incidence ranged from 0% among housekeeping workers to 38% among dental staff. Exposure of these sensitized individuals to latex caused itching in 84%, a skin rash in 68%, urticaria in 55%, lachrymation and ocular itching in 45%, nasal congestion in 39% and sneezing in 34%. Anaphylaxis occurred in 10.5%.
In a similar study at the University of Oulo in Finland, 56% of 534 hospital employees who used protective latex or vinyl gloves on a daily basis had skin disorders related to the usage of the gloves (Kujala and Reilula 1995). Rhinorrhoea or nasal congestion was present in 13% of workers who used powdered gloves. The prevalence of both skin and respiratory symptoms was significantly higher among those who used the gloves for more than 2 hours a day.
Valentino and colleagues (1994) reported latex induced asthma in four health care workers in an Italian regional hospital, and the Mayo Medical Center in Rochester Minnesota, where 342 employees who reported symptoms suggestive of latex allergy were evaluated, recorded 16 episodes of latex-related anaphylaxis in 12 subjects (six episodes occurred after skin testing) (Hunt et al. 1995). The Mayo researchers also reported respiratory symptoms in workers who did not wear gloves but worked in areas where large numbers of gloves were being used, presumably due to air-borne talcum powder/latex protein particles.
Control and Prevention
The most effective preventive measure is modification of standard procedures to replace the use of gloves and equipment made with NRL with similar items made of vinyl or other non-rubber materials. This requires involvement of the purchasing and supply departments, which should also mandate the labelling of all latex-containing items so that they may be avoided by individuals with latex sensitivity. This is important not only to the staff but also to patients who may have a history suggestive of latex allergy. Aerosolized latex, from latex powder, is also problematic. HCWs who are allergic to latex and who do not use latex gloves may still be affected by the powdered latex gloves used by co-workers. A significant problem is presented by the wide variation in content of latex allergen among gloves from different manufacturers and, indeed, among different lots of gloves from the same manufacturer.
Glove manufacturers are experimenting with gloves using formulations with smaller amounts of NRL as well as coatings that will obviate the need for talcum powder to make the gloves easy to put on and take off. The goal is to provide comfortable, easy to wear, non-allergenic gloves that still provide effective barriers to the transmission of the hepatitis B virus, HIV and other pathogens.
A careful medical history with a particular emphasis on prior latex exposures should be elicited from all health care workers who present symptoms suggestive of latex allergy. In suspect cases, evidence of latex sensitivity may be confirmed by skin or serological testing. Since there is evidently a risk of provoking an anaphylactic reaction, the skin testing should only be performed by experienced medical personnel.
At the present time, allergens for desensitization are not available so that the only remedy is avoidance of exposure to products containing NRL. In some instances, this may require a change of job. Weido and Sim (1995) at the University of Texas Medical Branch at Galveston suggest advising individuals in high-risk groups to carry self-injectable epinephrine to use in the event of a systemic reaction.
Following the appearance of several clusters of latex allergy cases in 1990, the Mayo Medical Center in Rochester, Minnesota, formed a multidisciplinary work group to address the problem (Hunt et al. 1996). Subsequently, this was formalized in a Latex Allergy Task Force with members from the departments of allergy, preventive medicine, dermatology and surgery as well as the Director of Purchasing, the Surgical Nursing Clinical Director and the Director of Employee Health. Articles on latex allergy were published in staff newsletters and information bulletins to educate the 20,000 member workforce to the problem and to encourage those with suggestive symptoms to seek medical consultation. A standardized approach to testing for latex sensitivity and techniques for quantifying the amount of latex allergen in manufactured products and the amount and particle size of air-borne latex allergen were developed. The latter proved to be sufficiently sensitive to measure the exposure of individual workers while performing particular high-risk tasks. Steps were initiated to monitor a gradual transition to low-allergen gloves (an incidental effect was a lowering of their cost by concentrating glove purchases among the fewer vendors who could meet the low allergen requirements) and to minimize exposures of staff and patients with known sensitivity to NLR.
To alert the public to the risks of NLR allergy, a consumer group, the Delaware Valley Latex Allergy Support Network has been formed. This group has created an Internet website (http://www.latex.org) and maintains a toll-free telephone line (1-800 LATEXNO) to provide up-to-date factual information about latex allergy to persons with this problem and those who care for them. This organization, which has a Medical Advisory Group, maintains a Literature Library and a Product Center and encourages the exchange of experiences among those who have had allergic reactions.
Conclusion
Latex allergies are becoming an increasingly important problem among health care workers. The solution lies in minimizing contact with latex allergen in their work environment, especially by substituting non-latex surgical gloves and appliances.