Proliferating in a wide range of manufactured goods—including an estimated 40,000 common household items—natural rubber latex has emerged over the last decade as an increasingly common trigger for anaphylaxis—producing allergies. Before the 1980s, reactions to latex were virtually unknown in the United States. Now, recent estimates put the incidence of latex sensitivity or allergy among the general US population at between 1% and 6%, or up to 16 million people.^1-3 Reasons for this increased incidence in latex allergies are attributable to biohazard precautions and manufacturing changes.

Defined as an allergy to natural rubber latex, a latex allergy may produce a range of skin reactions, from dermatitis to immediate hypersensitivity, depending at least partially on the degree of latex sensitization.

You can find more information about diagnosing and treating latex allergies, as well as understanding who is at risk for developing latex allergies in More About Latex.

 
Reasons for Increased Incidence

Biohazard precautions and manufacturing changes account for a large proportion of the recent increases in the incidence of latex allergy.

Biohazard precautions
It is commonly acknowledged that the sudden, large-scale increase in latex glove use by health care workers since the 1980s lies at the heart of the growing problem of latex allergy. As health care workers sought to protect themselves from AIDS and other blood-borne diseases, latex glove use became virtually universal in hospitals and other medical and dental facilities. Patients, and especially health care workers, were exposed to more latex than ever before, and many have become sensitized to it.

Manufacturing changes
To keep up with increased demand, manufacturers sped up their processes and resorted to lower-quality latex, both of which have resulted in latex products with higher levels of the protein that can trigger allergic reactions.

 
Definition

Latex allergy is a systemic allergic sensitivity to the proteins in natural rubber latex (NRL) that often worsens with each exposure and at its most severe can result in deadly anaphylaxis. Unlike synthetic latex, which rarely causes allergic reactions, NRL comes from the milky sap of rubber trees. Using various processing methods, NRL is used alone or in combination with other materials to make thousands of products including:

• Car tires
• Rubber bands
• Elastic
• Carpet backing
• Hospital and dental equipment

Dipped latex products are the biggest culprits in triggering allergic reactions, including:

• Gloves
• Balloons
• Condoms

 
Allergic Sensitization

Sensitization occurs when exposure to latex proteins causes the body's immune system to develop antibodies to these proteins. Because the body perceives the protein as a threatening foreign substance, it prepares to launch a defense against it in future encounters. Therefore, people may have been sensitized to latex without having yet shown external allergic symptoms. They are, however, at risk of becoming increasingly sensitized and eventually symptomatic if exposure to latex continues.

 
Reactions to Latex

Because latex can cause local skin irritation, or dermatitis, as well as systemic allergic reactions, it is important to differentiate between them so that the symptoms of potentially fatal allergic reactions are recognized and treated and proper precautions against future reactions are taken.

 
Dermatitis

Two types of skin irritations, or dermatitis, are common among frequent users of latex products, particularly glove-wearing health care workers:

• Irritant-contact dermatitis
  Raw, inflamed, even blistered skin that can also be caused by frequent hand washing, wearing nonbreathable gloves, and exposure to irritating chemicals.

• Allergic-contact dermatitis (delayed hypersensitivity)
  Allergic reactions that result in a delayed skin rash is similar to that caused by poison ivy. In contrast to systemic latex allergy, antibody mediation is not involved, therefore an immediate reaction does not occur. Because these reactions may be caused by the chemicals used in producing latex rather than by the latex itself, changing to a different brand of latex products that uses different processing chemicals may clear up the reaction.

While annoying, none of these reactions is dangerous per se, or is necessarily directly related to latex. There can, however, be progression from dermatitis to latex allergy. Severe skin irritation can make a person more susceptible to developing an allergic hypersensitivity to latex because the skin no longer protects more sensitive internal tissues of the body, which are more vulnerable to sensitization.

Latex allergy (immediate hypersensitivity)
True latex allergy occurs when the body's immune system becomes sensitized to latex proteins, usually over the course of repeated exposures. As a result of sensitization, the immune system overreacts to latex as a hostile substance. Allergic symptoms range from irritating to life-threatening, becoming progressively worse with repeated exposures.

Allergic symptoms include the following, and may occur singly or in combination:

• Itchy rashes, hives
• Nasal congestion (rhinitis)
• Swelling, especially around the nose, mouth, and throat
• Eye irritation or conjunctivitis
• Respiratory problems, including asthma and rhinoconjunctivitis
• Full-blown anaphylaxis, which can include any of the above, can cause death through suffocation or a severe drop in blood pressure

Since it is impossible to predict when an allergic reaction might escalate into deadly anaphylaxis, and because it can take only minutes to do so, it is important to take even seemingly mild allergic reactions seriously. Thus, those who have experienced allergic symptoms in response to latex should avoid further contact with it, and consult their physicians about carrying self-injectable epinephrine with them for anaphylactic emergencies.

 
References

1. Ownby DR, Ownby HE, et al. The prevalence of anti-latex IgE antibodies in 1000 volunteer blood donors. J Allergy Clin Immunol. 1996;97:1188-1192.
    
2. Kelly KJ, Sussman G, Fink JN. Stop the sensitization. J Allergy Clin Immunol. 1996;98:857-858.
    
3. Arellano R, Bradley J, Sussman G. Prevalence of latex sensitization among hospital physicians occupationally exposed to latex gloves. Anesthesiology. 1992;77:905-908.