The Incidence of Latex Sensitivity in Ambulatory Surgical Patients

Latex allergy

Allergy to natural rubber latex is an important clinical condition that occurred after the institution of universal precautions to protect healthcare workers. A rapid increase and production of both examination and surgical gloves resulted in an epidemic of allergy to latex protein. Healthcare workers in both the medical and dental environments, as well as specific groups of individuals including those with spina bifida, myelodysplasia, and food allergies (banana, kiwi, avocado, and others), were at increased risk of sensitization. Clinical symptoms in the latex allergic individual ranged from type I hypersensitivity reaction including rhinoconjunctivitis, asthma, and systemic reaction to type IV hypersensitivity reaction, which occur from the chemicals added during the manufacturing process. Diagnosis of latex allergy is based on a clinical history that correlates the development of symptoms in relationship to exposure. In the United States there are no skin tests approved by the Food and Drug Administration. Therefore a combination of clinical judgment and serologic testing such as ImmunoCAP and Immulite is helpful. The primary treatment of latex allergy is avoidance of exposure to the latex protein.

Latex allergy, a special risk for patients of otorhinolaryngology and head and neck surgery?

A total of 206 patients of the otorhinolaryngology (ORL) department and 204 of the visceral surgery department of the Ludwig Maximilians University of Munich were preoperatively evaluated for latex-specific sensitization. A prick test, a questionnaire, and an enzyme-linked immunosorbent assay immunoprecipitation for IgE antibodies were performed. Latex is a widely spread allergen, and it does not only concern healthcare populations. Within the ORL surgery group, 43 (20.9%) patients were sensitized against latex allergen, and 2 of them were reported to manifest symptoms in consorting with latex. In the cohort of visceral surgery patients, we detected only 23 patients (11.3%) with sensitization against latex. Moreover, most patients were positively detected with the skin prick test (86.4%), whereas the enzyme-linked immunosorbent assay method was less sensitive (18.3%). Patients of the ORL department were considerably more frequently exposed to latex protein particles than patients of the visceral surgery department. This difference attributes to their significant difference in mean age: 44 years in the ORL patients group versus 58 years in the visceral patients cohort. Furthermore, we did not find any correlation to the number of past operations--although undergoing any surgical procedures is a well-known risk factor in other studies about latex sensitization in surgical patients.

Occupational allergies caused by latex

Allergy to natural rubber latex is an important cause of occupational allergy in healthcare workers. Disposable medical gloves are the major reservoir of latex allergens, particularly powdered gloves, in healthcare delivery settings. Diagnosis of latex allergy requires a history of exacerbation of cutaneous, respiratory, ocular, or systemic signs and symptoms after exposure to natural rubber latex products; and evidence of sensitization by patch testing, skin testing, measurement of latex-specific IgE antibodies, or challenge testing. Optimal management of latex allergy involves education concerning cross-reacting allergens, reduction of cutaneous or mucosal contact with dipped rubber products, and minimization of exposure to latex aeroallergens in work environments.

Have health conditions associated with latex increased since the issuance of universal precautions?

OBJECTIVES

This study explored whether the prevalence of latex-related health conditions has increased among individuals employed in medical occupations relative to those employed in nonmedical occupations since the issuance of universal precautions in 1987.

METHODS

Data derived from the 1983 to 1994 versions of the National Health Interview Survey were used to obtain odds ratios comparing prevalence rates of latex-related symptoms over time.

RESULTS

No statistical evidence was found that the universal precautions resulted in increased prevalence rates of latex-related health conditions among medical workers relative to those employed in nonmedical occupations.

CONCLUSIONS

Increased use of latex gloves among health care personnel subsequent to the implementation of universal precautions appears to have had no effect on latex allergic reactions experienced by these workers.

Latex allergy: the perspective from the surgical suite

Latex allergy in the perioperative setting presents unique challenges to the health care system. Specific needs of the latex-sensitive patient are paramount, but consideration must also include the impact on health care workers vis-a-vis latex sensitization, environmental allergen control, and barrier protection against blood-borne pathogens. It has been well documented that the greatest source of latex aeroallergen in the surgical setting is latex gloves (both sterile and nonsterile). Levels of latex aeroallergen correlate strongly with use of high-allergen and powdered gloves, total number of gloves used, and the hours of activity in a given environment. A significant reduction in aeroallergen (>10-fold) can be achieved by switching to low-allergen gloves. Ready availability of and encouragement to use nonlatex alternatives when appropriate can further reduce exposure to latex allergens. Since 1998, the Food and Drug Administration has required all medical devices (or their packaging) that contain natural rubber latex to be so labeled. In addition, industry has responded with a host of latex-free products for use in patient care. This has helped eliminate a great deal of confusion about which products are safe for use with latex-sensitive individuals. However, despite significant efforts to educate the public and the health care industry regarding latex allergies, considerable misinformation persists. Provision of a completely latex-free environment in most surgical suites may be unrealistic, but every effort should be made to minimize the unnecessary exposure of patients and health care workers to latex allergens in this high-risk arena.

A blinded, multi-center evaluation of two commercial in vitro tests for latex-specific IgE antibodies

PURPOSE

To compare the diagnostic value of two commercial in vitro tests for the detection of latex-specific IgE antibodies.

METHODS

Serum samples were collected from latex-allergic and nonlatex-allergic individuals. Persons were classified as latex allergic if they had a positive clinical history and a positive skin prick test with a latex extract. Persons with no latex-related symptoms and negative skin tests were classified as nonlatex allergic. The serum samples were tested in a blinded fashion by a laboratory using the CAP (Pharmacia-Upjohn) and AlaSTAT (Diagnostic Products Company) assays. Values of 0.35 kA U/L or greater were considered positive in both tests.

RESULTS

The 143 sera studied came from 83-latex allergic and 60 nonallergic persons. The in vitro tests were found to have sensitivities of 79.5% and 73.8%, and specificities of 90.2% and 91.7%, for CAP and AlaSTAT, respectively. The positive predictive values were 91.7% and 92.5%, while the negative predictive values were 76.4% and 71.4% for the CAP and AlaSTAT, respectively.

CONCLUSION

In individuals classified by the combination of clinical history and skin test results, both the Pharmacia CAP and the DPC AlaSTAT demonstrated acceptable sensitivities, specificities, and predictive values for detection of antilatex IgE antibodies. These findings suggest that both assays can be useful adjuncts to the diagnosis of latex allergy.

Prevalence of IgE to natural rubber latex in unselected blood donors and performance characteristics of AlaSTAT testing

BACKGROUND

The prevalence of IgE to natural rubber latex (NRL) proteins in the general population remains unsettled, both because of the difficulty of obtaining an unbiased population representative of the general population of the United States and because of concerns about the reproducibility of tests for anti-latex IgE antibodies. Establishing the prevalence in the population is important toward defining the potential risks of persons entering areas where latex exposure may occur.

OBJECTIVE

The purposes of this study were to determine the prevalence of IgE to latex in a general population and to assess the performance characteristics of the AlaSTAT microtiter plate test for anti-latex IgE when performed independently by different laboratories.

METHODS

One thousand nine hundred and ninety-seven consecutive blood samples obtained from the Oklahoma Blood Institute were assayed independently in three laboratories for IgE to NRL using the FDA-approved AlaSTAT ELISA for IgE to NRL. The group consisted of 56% men and 44% women. Ninety percent were Caucasian, 4% African American, and 6% were "other."

RESULTS

The prevalence IgE to NRL between the 3 laboratories varied from 5.4% to 7.6% at the designated cut off of 0.35 kU/L. Examination of results for specific individuals demonstrated >90% agreement between the three sites with the most reproducible results at the Class II cutoff of > or =0.7 kU/L. There was no difference in the percent of positive values at the three laboratories.

CONCLUSIONS

There is good agreement between laboratories as to NRL IgE reactive and non-reactive sera using the AlaSTAT test. This report of the largest sample of blood donors confirms earlier reports as to the prevalence of IgE NRL in blood donors.