Also known as Immediate Type Hypersensitivity, Protein Allergy or Type I
Whilst natural rubber latex allergy is comparatively scarce, it is possibly the most feared due to its potential to cause anaphylactic shock. In common with allergic contact dermatitis, it is dose and rate dependent. Immediate Type Hypersensitivity is an immunoglobulin E (IgE) antibody mediated allergy and only those individuals that are genetically predisposed to sensitization to a specific latex protein are vulnerable. Of the reported 250 protein peptides in raw latex, about 50 are reported to have the allergenic potential capable of inducing the production of IgE antibodies. Successive challenges by the specific latex protein allergen increases the production of IgE antibodies and leads to increasing sensitization of cells. Clinical symptoms develop when the individual’s unique “symptom threshold limit” is reached. Once a person’s symptom threshold level is reached, subsequent contact with the specific protein allergen causes the sensitized cells to release immunological mediators such as histamine.
When discussing the mechanism of Protein Allergy, it is important to understand the correlation between food allergies and latex protein allergies. Individuals who are allergic to food like avocados, bananas, cherries, chestnuts, kiwis, melons, peaches, pears, tomatoes etc. may have a higher probability of developing a latex protein allergy. In view of the cross-reactivity between natural rubber latex protein allergens and many commonly encountered plant allergens, any individual presenting with one or more food allergies should be screened for natural rubber latex allergy. Similarly whilst the traditional sources of exposure to natural rubber latex allergy in the laboratory are direct skin or mucosal contact, glove powder can be an important vector for triggering reactions generated by inhalation of aerosolized allergens.
Symptoms of Protein Allergy
Once an individuals’ symptom threshold is reached, the onset of symptoms may occur within minutes to an hour after exposure to the allergen(s), hence the alternative name for natural rubber latex allergy of immediate type hypersensitivity1)Warshaw E.M. (1998) “Latex Allergy” Journal of the American Academy of Dermatology July, 39:1. The initial symptoms of natural rubber latex allergy are often itching and tingling, but with time may present in various forms and are summarized in the table below. The potential of this reaction to exhibit systemic symptoms and progress to anaphylactic shock is unique to natural rubber latex allergy. The profile of Protein Allergy is shared with penicillin, shellfish and peanut allergies.
Symptoms of natural rubber latex allergy
|Abdominal cramps||Allergic rhinitis||Anaphylactic shock||Asthma-like symptoms|
|Diarrhoea||Allergic conjunctivitis||Cardio-respiratory arrest||Bronchospasm|
|Hives/urticaria (anywhere)||Facial & laryngeal oedema||Hypotension||Difficulty breathing|
|Nausea/vomiting||Rapid heart rate|
Proposed action for managing natural rubber latex allergy
The potentially serious symptoms associated with natural rubber latex means that this reaction is likely to remain in the spotlight. Reports by the TUC that natural rubber latex allergy is the third leading cause of occupational asthma in Europe2)Trades Union Council Report (2001) “Rubber banned? The case against latex” [on line], London. Available from www.tuc.org.uk/h_and s/tuc-3250-f0.cfm [accessed 27th September 2006]and encouragement by the Health & Safety Executive to seek latex-free solutions3)Health and Safety Executive “I work in a laboratory” [on line]. Available from www.hse.gov.uk/latex/labs.htm (accessed 27th September 2006) means that this trend is likely to continue. Against this view is the increasing evidence emerging from Germany4)Allmers H., Schmengler J. and Skudlik C. (2002) “Primary Prevention of natural rubber latex allergy in the German Health Care System through education and intervention” J. Allergy Clin. Immunol. 110 (2):318and Finland5)Turjanama K., Kanto M., Kautiainen H., Reunala T. and Palosuo T. (2002) “Long term outcome of 160 adult patients with natural rubber latex allergy” J. Allergy Clin. Immunol. 110: S70-74suggesting that wearing low protein non- powdered natural rubber latex gloves greatly reduces the risk of allergic reactions. Likewise the comfort and barrier properties of natural rubber latex (particularly to biohazards and aqueous liquids) are well documented. However, for laboratory staff it should be noted that the risk of natural rubber latex allergy is likely to be higher than that for the general population, as repeated use of natural rubber latex gloves can increase the risk of sensitization. In addition, the widespread use of organic solvents in the laboratory may render natural rubber latex unsuitable for use.
- Notify your supervisor.
- Consult Occupational Health.
- Avoid contact with products made from natural rubber latex (e.g. rubber bands, surgical masks, syringes, tubing etc) and wear synthetic gloves.
- Request that individuals wearing gloves in the workplace, use only powder-free latex or synthetic gloves.
- Notify your colleagues, GP and dentist of this allergy – wear a medic alert bracelet.
- Learn to recognize the symptoms of natural rubber latex allergy.
- Be aware that symptoms may develop after contact with cross-reactive allergens.
Other management action controlling the risk of natural rubber latex allergy
As mentioned earlier natural rubber latex gloves remain an attractive proposition in terms of comfort and cost-effectiveness, whilst for the majority of the general population there is no risk of natural rubber latex allergy. In addition the suitability of natural rubber latex gloves for the laboratory will be determined by a risk-assessment. However, there are some effective measures that can significantly reduce the risk of natural rubber latex allergy:
- Implement a powder-free laboratory environment.
- Source only gloves which are low in latex-protein content. Test data should be current and have been performed by a reputable independent laboratory.
- In Europe test methodology will typically be based on the EN455-3 Modified Lowry method, which will provide total amount of protein (whether it is from natural rubber latex or any other source). Given that natural rubber latex allergy is dose and rate dependent and there is a correlation between exposure levels and the speed at which one reaches the critical threshold, lower levels of latex protein can be expected to reduce the risk of developing natural rubber latex allergy. In this context, the HSE qualifies low protein natural rubber latex gloves as those with less than 50 µg/g6)Health and Safety Executive “About latex allergies” [on line]. Available from www.hse.gov.uk/latex/about.htm (accessed 27th September 2006).
- Whilst the Modified Lowry assay appears to be the most widely recognized test for latex protein, other tests specific to latex protein exist. One such test is the ELISA Inhibition or the LEAP (Latex ELISA for antigenic protein) assays, which measures only latex proteins that the body can recognize (antigenic). Test results are expressed as microgram of antigenic protein per gram of glove (µg/g). LEAP is now incorporated into a US standard based on ASTM D6499 “Test Method for the Immunological Measurement of Antigenic Protein in natural rubber and its products” and may provide a useful complement to the Modified Lowry method.
- Natural rubber latex allergenic protein may be measured by the RAST or Radioallergosorbent Test. This is an in vitro or test tube test used to identify and quantify latex specific IgE antibodies in patient serum or latex allergens from product extracts, depending on the way in which the test is conducted.
References [ + ]
|1.||↑||Warshaw E.M. (1998) “Latex Allergy” Journal of the American Academy of Dermatology July, 39:1|
|2.||↑||Trades Union Council Report (2001) “Rubber banned? The case against latex” [on line], London. Available from www.tuc.org.uk/h_and s/tuc-3250-f0.cfm [accessed 27th September 2006]|
|3.||↑||Health and Safety Executive “I work in a laboratory” [on line]. Available from www.hse.gov.uk/latex/labs.htm (accessed 27th September 2006|
|4.||↑||Allmers H., Schmengler J. and Skudlik C. (2002) “Primary Prevention of natural rubber latex allergy in the German Health Care System through education and intervention” J. Allergy Clin. Immunol. 110 (2):318|
|5.||↑||Turjanama K., Kanto M., Kautiainen H., Reunala T. and Palosuo T. (2002) “Long term outcome of 160 adult patients with natural rubber latex allergy” J. Allergy Clin. Immunol. 110: S70-74|
|6.||↑||Health and Safety Executive “About latex allergies” [on line]. Available from www.hse.gov.uk/latex/about.htm (accessed 27th September 2006|