Facts about Latex Allergy
by Mark Schweder, MSPH, CIH
Types of Latex Reactions
There are three types of undesirable reactions that have been associated with exposure to latex products, usually latex gloves. These are known as 'irritant contact dermatitis', 'Type IV chemical hypersensitivity’, and 'Type I latex-protein hypersensitivity’. Irritant contact dermatitis and Type IV chemical hypersensitivity are common reactions caused by the chemicals used to provide strength and elasticity to the gloves [1]. The discussion here will focus on the Type I latex protein hypersensitivity. These reactions are caused by direct contact with latex proteins, which may be absorbed through the skin and carried into the bloodstream where an immune system response occurs [2]. Allergic reactions to latex are diverse; they range from skin disease to asthma. Anaphylactic shock can develop in rare cases.
Predisposing Factors for Latex Allergy
Factors, which predispose an individual to latex allergy, include a history of other allergies (such as hives or hay fever) and frequent exposure to latex products. 'Sensitization' to latex proteins doesn't happen after a single exposure; instead, the worker usually becomes gradually sensitized after repeated exposures [3]. Antibodies slowly build up until there is enough present to produce an antigen / antibody reaction that produces symptoms. Progression of symptoms can advance very rapidly or take years.
The following illustrates a potential scenario under which the evolution of a latex allergy can occur. It is important to note that individuals can show different clinical patterns.
Phase |
Symptoms |
I |
None |
II |
Contact dermatitis (itching, dryness, possible cracking of skin, usually involves only the hands) |
III |
Presence of itching and hives (localized skin rash and swelling of skin), throughout different regions of the body |
IV |
Allergic Rhinoconjunctivitis (similar to hay fever, involves sneezing, nasal congestion, runny nose, watery eyes, scratchy throat) |
V |
Asthma |
VI |
Anaphylactic shock |
Sensitization to Latex Proteins
Attempts have been made to quantify the numbers of persons who have a sensitization to latex without any symptoms. One such method of determining sensitization is done by skin prick testing, which can be done to identify persons with a sensitization to latex but not symptoms [2].
A positive reaction is indicated by swelling or redness at the test site within minutes of application. In one study, researchers used the skin test to evaluate 168 anesthesiologists for the presence of latex allergy [3]. Two-and-a-half percent had clinical symptoms, while twelve-and-a-half percent had a positive skin test, meaning that 10 percent had sensitization but are not showing symptoms yet.
More specifically, these individuals have produced IgE antibodies. When these antibodies encounter latex proteins under the right circumstances, they can possibly cause a serious allergic reaction
Once an individual has developed latex allergy, they should try to totally avoid exposure to latex to prevent worsening of symptoms [4]. Persons that experience severe reactions should have their home and work environment carefully evaluated for the presence of latex, because even minute quantities can cause a reaction in sensitized persons [5].
Exposure Limits and Air Sampling for Latex
Quirce and Swanson et al have published guidelines for recommended airborne levels of latex allergen that could elicit a response in sensitized persons (6). For air samples (in nanograms of latex allergy per cubic-meter of air); less than 10 is considered "low"; 10 to 50 is considered "moderate"; and greater than 50 is considered "high". “Low” indicates an acceptable air sample, “moderate” merits some concern, and “high” warrants immediate action.
A significantly less rigorous guideline has been set by the American Conference of Governmental Industrial Hygienists (ACGIH). The ACGIH Threshold-Limit-Value (TLV) of 1 microgram per cubic meter (µ/m3) is 100 times higher than the “Low” limit proposed by Quirce and Swanson et al (note that 1 microgram equals 1,000 nanograms) (American Conference of Governmental Industrial Hygienists 2005).
Specialized air sampling equipment is required to collect latex proteins from the air. The preferred method uses a sampling pump with a polytetrafluoroethylene filter. Lots of air must be sampled to achieve low detection limits (at least 10,000 liters).. The preferred analysis method uses a quantitative immunoassay and IgE antibodies to measure the amount of latex protein in the air (7).
Risk Tech can perform a Latex Audit and Risk Assessment for your facility. Feel free to contact us for more information.