Managing Occupational Allergies Curtis P. Hamann, MD; Pamela A. Rodgers, PhD; Kim Sullivan

About three percent of dental patients are probably healthcare professionals (U.S. population and labor statistics) and are at risk for having certain occupationally related allergies. Therefore it is not surprising the new Guidelines for Infection Control in Dental Health-Care Settings – 2003 included recommendations and extensive information about contact dermatitis and latex hypersensitivity applicable to both dental workers and their patients. These recommendations from the Centers for Disease Control and Prevention (CDC) can be summarized as follows:

• Educate dental workers about skin problems from frequent hand hygiene, glove use, and chemical exposure.

• Screen dental patients for latex allergy.

• Provide a latex-safe environment for dental workers and patients with a latex allergy.

• Equip the dental office with emergency kits that contain latex-safe products.

A ‘latex’ allergy is defined as an immune reaction to natural rubber latex (NRL) proteins, but known clinically as a type I NRL hypersensitivity. This allergic reaction is due to circulating antibodies that attack foreign NRL proteins contained in NRL products such as gloves. Symptoms occur rapidly, including sneezing, itchy eyes, and hives (Table 1). Severe reactions can progress to life-threatening anaphylaxis requiring urgent medical care.

Studies at the Mayo Clinic and University of Toronto indicate latex allergy prevalence has diminished lately in dentistry and medicine (L.W. Hunt et al., 2002 and M.J. Saary et al, 2001). Once estimated to affect 10%-20% of healthcare workers, the prevalence now seems closer to five percent. This change may be due in part to the use of low-allergen latex, powder-free latex, and synthetic rubber gloves.

In comparison to latex allergy, allergic contact dermatitis (ACD) is more common, affecting more than 20% of healthcare workers due to frequent chemical exposure. These chemicals can be found in dental, medical, and consumer items such as disinfectants, sterilants, soaps, and hand lotions, as well as gloves and rubber products. Itching, redness, vesicles, dry skin, fissures and sores, can be symptoms of ACD, also known clinically as type IV hypersensitivity (Table 1).

In contrast to latex allergy, ACD reactions are confined to the area of direct chemical contact, develop slowly and persist for several weeks. As with other allergies, ACD reactions are mediated by the immune system. Chemicals most likely to elicit ACD in dental workers include methacrylates in dental bonding agents, thiurams and carbamates in rubber gloves, and various antimicrobials such as glutaraldehyde, thimerosal, benzoic acid, formaldehyde and glyoxal (L.M. Wallenhammer et al., 2000; K. Wrangsjo et al., 2001; A. Schnuch et al., 1998).

At the forefront of the 2003 CDC recommendations is education. Dental professionals must understand the risk factors, symptoms, diagnostic process, and management strategies for these occupational allergies. A recent survey of hospital employees showed that without ongoing education, 80% of workers continued to have skin and respiratory symptoms related to occupational allergies. Numerous educational resources are available, including continuing online education courses or at regional and national dental conferences. The recently published CDC guidelines also provide an excellent resource on contact dermatitis and latex allergy.

Screening dental patients (and workers) for a latex allergy is best accomplished through the use of a detailed health history questionnaire. Key questions to address: 1) existing allergies or allergic reactions (for example food, pollen or insect venom); 2) regular exposure to rubber products such as gloves; 3) previous reactions to rubber; and 4) the presence of spina bifida or multiple childhood surgeries (Table 1). Workers or patients with symptoms, reactions or risk factors consistent with ACD or latex allergy should be forwarded to a physician for evaluation. Their diagnosis should include a combination of skin prick or blood testing for latex allergy (type I NRL hypersensitivity), and patch testing for ACD to dental chemicals.

Latex-allergic workers and patients must avoid NRL allergens. Latex-safe environments should be provided (see the 2003 Guidelines) and patients may benefit from early morning appointments when airborne NRL allergens are lowest. Latex-allergic individuals should identify NRL-containing products at work and at home and find appropriate alternatives made with nitrile, neoprene, vinyl, polyurethane or styrene-based materials. Airborne NRL allergens in the dental office must also be reduced with office and air duct cleanings and the use of powder-free low protein NRL gloves, or synthetic gloves in either powdered or powder-free styles. Remember also that latex-free emergency medicines and supplies should be current, accessible, and easily identified.

Dental workers and patients with ACD to certain chemicals must also manage their allergy through avoidance. With the help of their dermatologist or allergist, individuals with ACD should know the allergen(s), and be able to recognize healthcare and consumer products that contain those chemicals. Individuals with ACD must also be aware of potential cross-reactivity, such as in methacrylates (bonding agents and glues), as well as thiurams and carbamates (natural and synthetic rubbers).

In summary, the new CDC guidelines provide solid recommendations for dental practitioners about proper hand hygiene. Healthy skin is an essential barrier against damage from abrasion, chemicals, and infectious agents. Towards that goal, effective management of occupational allergies is essential.

About the Authors:

Dr. Curt Hamann received his medical degree from Loma Linda University. He is currently the CEO and Medical Director of SmartPractice. As an authority on rubber-based allergies and glove manufacturing, Dr. Hamann has developed novel latex-free polymers for use in medical gloves. His expertise in gloves, infection control, and hand hygiene is highlighted by his contribution to the 2003 CDC dental infection control guidelines. Dr. Hamann is also committed to preventive dentistry and medicine, and improving patient communication. He is published in several peer-reviewed journals and speaks throughout the world on occupational allergies, infection control, and patient communication.

Dr. Pamela Rodgers helped translate ‘benchtop’ science into ‘bedside’ treatments for jaundice in her graduate and postgraduate studies at the University of California, Davis, and Stanford University. She now writes extensively about disease prevention and occupational health and helps coordinate research for SmartPractice, supporting their corporate mission to improve healthcare practice around the world.

Kim Sullivan, Vice President of Regulatory Affairs & Clinical Research, has helped research and encourage education about occupational rubber-based allergies for medical and dental professionals. She has worked with infection control, dental and medical organizations throughout the country to improve the health of workers and patients through increased awareness and diagnosis-driven management.

Works Cited:

1. Wrangsjo K, Swartling C, Meding B. Occupational dermatitis in dental personnel: contact dermatitis with special reference to (meth)acrylates in 174 patients. Contact Dermatitis (Copenhagen) 2001;45:158-63.

2. Schnuch A, Uter W, Geier J, Frosch PJ, Rustemeyer T. Contact allergies in healthcare workers. Results from the IVDK. Acta Dermato-Venereologica (Stockholm) 1998;78:358-63.

3. Saary MJ, Kanani A, Alghadeer H, Holness DL, Tarlo SM. Changes in rates of natural rubber latex sensitivity among dental school students and staff members after changes in latex gloves. Journal of Allergy and Clinical Immunology 2002;109:131-5.

4. Hunt LW, Kelkar P, Reed CE, Yunginger JW. Management of occupational allergy to natural rubber latex in a medical center: the importance of quantitative latex allergen measurement and objective follow-up. Journal of Allergy and Clinical Immunology 2002;110:S96-106.

5. Wallenhammar LM, Ortengren U, Andreasson H, Barregard L, Bjorkner B, Karlsson S et al. Contact allergy and hand eczema in Swedish dentists. Contact Dermatitis (Copenhagen) 2000;43:192-9.