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By: Vince McLeod, CIH, Glenn Ketcham, CIH  
Issue: August/September 2005

Gloves are a primary defense in preventing exposures and transmission of many infectious and harmful agents. Since the introduction of “universal precautions” for safeguarding against blood-borne pathogens in the 1980’s glove use has grown exponentially. In many forensic settings, either in the field or in the lab, use of the latex examination glove has become the norm. But for some workers, wearing the disposable latex gloves may produce allergic reactions. Reports on the prevalence of latex allergy vary greatly. Recent scientific literature indicate rates up to 11% for non-health care workers exposed to latex at work.1 Read on to learn the causes, symptoms, treatment, and prevention of latex allergy and associated dermatitis reactions.

What is latex and what is latex allergy?
Natural rubber latex, refered to as “latex,” is the product manufactured from the milky sap extracted from the rubber tree, Hevea Brasiliensis, found predominately in Africa and South East Asia. Latex is made up of many chemicals but the proteins found in the rubber are the culprits leading to the more serious allergic reactions. The manufacturing process can remove most of these proteins. However, due to the huge demand, many poor quality gloves have materialized on the market. Additionally, the manufacturing processes use organic chemicals including carbamates, mercaptobenzothiazole, and thiurams as acceleration agents, further increasing the potential for allergic reactions for workers wearing latex gloves.

Simply stated, latex allergy is a reaction to the proteins in latex rubber. It is unknown how much exposure is needed to produce an allergic reaction or sensitization but, increasing the exposure increases the risk of developing symptoms. Fortunately, true latex allergy is rare as you will see. Unfortunately, there are two other types of reactions that can occur and these are much more prevalent.

Different Latex Reactions
The single most common reaction to latex products is called irritant contact dermatitis (ICD) also known as eczema or just dermatitis. As the name indicates, this type of reaction is caused by irritation from wearing and using protective gloves and by exposure to the powders inside them. It is not caused by an allergy to the latex proteins or other chemicals contained in the latex. Frequent use of antiseptic or germicidal agents, or constant washing and drying of the hands may deplete the natural oils and dry out the skin. The alkaline nature of many soaps act to strip away the protective acid mantle of the skin. Sweating and rubbing also contribute to skin irritation. Finally, the powders added to gloves for easier donning are one of the leading causes of ICD.

Symptoms of ICD are often dry, itchy, cracked, scaly skin, usually on the hands. Redness, swelling, and blistering may also occur. Symptoms are usually limited to the areas covered by the gloves.

Allergic contact dermatitis is sometimes called chemical sensitivity dermatitis. It is a response to the chemical accelerants in the latex mentioned above which are referred to as contact sensitizers. Other common contact sensitizers include disinfecting agents and soaps. Technically referred to as Type IV delayed hypersensitivity, CSD appears as a rash with blisters (similar to poison ivy) and usually peaks within 48 hours. People with chronic skin damage are at increased risk and with repeated contact, progression spreads beyond the border of the gloves. Neither chemical sensitivity dermatitis nor irritant contact dermatitis is a true allergy.

True latex allergy, technically named immediate Type I hypersensitivity, can produce severe reactions in workers exposed to latex. Auspiciously, it is much less common than the dermatitis reactions. A Type I reaction is a systemic response caused by repeated exposure to a specific allergen, i.e. the latex proteins. Triggered by exposure to some threshold level, a flood of histamine and other factors are released causing vasodilatation and bronchoconstriction. Symptoms usually begin within minutes of exposure in sensitized persons but, they can occur hours later and be widely varied. Skin flushing, rashes, hives, or itching are examples of mild reactions. Severe reactions include itchy swollen eyes, runny nose, sneezing, scratchy throat, and asthma (difficult breathing, coughing, and wheezing). Very rarely, anaphylactic shock has occurred but this is seldom the first sign of latex allergy.

Damaged or broken skin can increase the risk for latex allergy and in many cases workers contract the dermatitis before developing the latex allergy. Also, a link has been demonstrated between increased susceptibility to latex protein allergy and allergic reactions to certain foods such as avocado, kiwi, banana, tomato, and papaya.
Absorption through the skin, the dermal route, is not the only exposure means for latex proteins. Breathing in the particles, the inhalation route, is possible as the proteins can become attached to the powders and then dispersed when the gloves are donned or removed. This can be a concern for any sensitized individual that happens to breathe the airborne particles.

Treatment and Prevention
The key to preventing long-term health effects is detecting symptoms early. Seek proper medical consultation at the first signs of trouble. Medications are available to treat the symptoms but complete latex avoidance is most effective. Special precautions are necessary to prevent subsequent exposures once a worker develops latex allergy.

Workers are often unaware of latex allergy risk in the workplace. This can result in potentially serious health problems. Minimize risk and prevent possible health problems by following these recommendations from NIOSH2:

• Use non-latex gloves (such as nitrile, PVC) whenever possible (e.g. non-infectious materials, routine housekeeping etc.).
• If latex gloves are the best choice, use powder-free gloves with reduced protein (<50 micrograms/gram extractable protein) and low levels of residual chemical accelerants.
• Develop and implement appropriate safe work practices to reduce chances of latex exposures.
• Develop and provide training to employees on latex allergy.
• Learn to recognize the symptoms of latex allergy.

We welcome your comments and questions. You can email us at thesafetyguys@forensicmag.com.

1. NIOSH (National Institute of Occupational Safety and Health): Preventing Allergic Reactions to Natural Rubber Latex in the Workplace, Publication #97-135, June 1997.

2. NIOSH (National Institute of Occupational Safety and Health): Latex Allergy A Prevention Guide, Publication #98-113, 1998.

Vince McLeod is a Certified Industrial Hygienist by the American Board of Industrial Hygiene and the senior IH with the University of Florida’s Environmental Health and Safety Division. He has 15 years of experience in all facets of occupational health and safety and specializes in hazard evaluation and exposure assessments.

Glenn Ketcham is a Certified Industrial Hygienist with 20 years experience in the health and safety field. He is currently the Risk Manager for the University of Florida. He has worked as a USDOL/OSHA compliance officer and has program management experience in general OSHA compliance, laboratory and chemical safety, workplace ergonomics, loss prevention, disaster preparedness, and classical industrial hygiene.