Natural rubber latex (NRL) is a unique and useful material. Its strength, elasticity, and impermeability have made it a key component of many household and industrial products. In the health care industry, NRL is used in the manufacture of a broad range of products, including gloves, catheters, drains, dental dams, and so on. NRL has been especially useful in the manufacture of medical gloves. These gloves must have excellent barrier properties to prevent the spread of infection associated with blood or secretions. However, they must also have excellent tactile properties, as sense of touch is extremely important in doing many medical procedures in areas such as surgery or dentistry. NRL gloves have worked exceedingly well in these applications over a period of many years.
Use of NRL gloves has massively increased since the late 1980s. The recognition of HIV infection and the institution of "universal precautions" to prevent the spread of infection between patients and health care workers was a major impetus for increased glove usage. This period of increased glove usage has been marked by increasing problems with NRL allergy. Not very long ago, NRL allergy was a relatively minor problem. The first case of NRL allergy referable to NRL glove use was not even reported until 1979. Subsequently, NRL allergy has grown in importance. For example, in the period from 1989 to 1992, the US Food and Drug Administration received more than 1100 reports of allergy and 15 reports of death due to anaphylaxis resulting from NRL exposure. In response to public health concerns about NRL allergy, the National Institute for Occupational Safety and Health (NIOSH) published a NIOSH Safety Alert entitled "Preventing Allergic Reactions to Natural Rubber Latex in the Workplace" in 1997. This publication describes the problem of NRL allergy, and provides recommendations for prevention and management of the condition.
This short review is focused on IgE-mediated NRL allergy in the health care setting and is intended to provide the environmental safety and health professional with the background and practical information needed to manage, and hopefully prevent, latex allergy. Background information will be provided about exposures to NRL; responses to NRL; and diagnosis, epidemiology, prevention, and management of NRL allergy. Frequently asked questions about NRL allergy will also be addressed. Finally, a short list of recommended readings is provided.
NRL is generally prepared from the milky, viscous latex of the rubber tree, Hevea brasiliensis. Latex is the cytoplasm of specialized tube-like cells, known as lactifers. It readily coagulates, in nature serving the function of sealing injuries to the rubber tree. H. brasiliensis latex is a complex mixture with many constituents. It contains rubber particles, which are largely composed of cis-polyisoprene encased in a lipoprotein envelope. It also contains organelles known as lutoids, which contain a fluid termed "B-serum" that is enriched for the protein hevein. Hevein plays an important role in coagulation of the latex.