Latex Allergy

Allergy to latex rubber, which is being increasingly recognized, creates two types of problems. The first is self-exposure in the workplace or home. Health care workers and patients need to be made aware that rubber is used widely in surgical gloves, anaesthetic facemasks, teats and bottle stoppers. In the home, rubber is in many products, including elasticized garments, balloons, elastic bands, mattresses, condoms and diaphragms. Education is vital to prevent exposure to such products. Also, awareness of nonlatex substitutes is helpful.

The second problem is passive exposure to latex, e.g. when latex-allergic subject is a patient undergoing medical investigations or surgery. To avoid this problem the patient must inform the staff beforehand of their sensitivity so that the staff wear non-latex gloves and only use equipment that contains no latex.

Concern about transmission of acquired immunodeficiency syndrome and hepatitis has greatly increased the use of latex gloves. Latex rubber allergy is a newly emerging problem with potential life-threatening sequelae among health care personnel, especially in workers with other allergies (i.e. atopics).

What is Natural Rubber Latex (NRL)?

NRL is a milky substance obtained from Hevea brasiliensis, the rubber tree, and is used to manufacture a wide variety of medical and consumer products. Most NRL is processed in dry form to produce vehicle tyres, some is used as a liquid to produce "dipped" products such rubber gloves, balloons, and condoms.

Other rubber products are produced from butyl or synthetic rubber, which is derived from petroleum. It is often difficult to determine whether a rubber product is made from natural rubber or synthetic rubber.

Products labeled as containing "latex" often do not contain natural rubber (e.g., latex paint).

Prevalence of Latex Allergy %

  • General population 2.5
  • Health care workers15
  • Dentists 4
  • Laboratory workers 3
  • Children with spina bifida 65

* Approximate percentages, derived from a number of studies throughout the world.

Children with spina bifida are at high risk because of multiple surgical procedures and catheterisations, with the opportunity of contact with rubber catheters and other instruments.

People who have a history of allergy to bananas, avocados, kiwi fruit, and water chestnuts are also at increased risk. Patients are also at risk – because latex is a component of many commonly used medical devices, including surgical and examination gloves, it behoves us to identify latex-sensitive patients and be prepared to treat allergic reactions promptly. There are also opportunities for contact with latex outside of the medical sphere, for example in balloons, toys, kitchen gloves and condoms. Identification of latex sensitive individuals can be life saving.

Clinical Features of Latex Allergy

Reactions to latex range from annoying rashes, to life-threatening anaphylaxis. In the USA more and more health care workers are being affected and claiming 100 percent disability.

Skin

  • Contact Urticaria (red papules on the dorsum of the hands, with intense itching) occurring within 10 minutes of putting the gloves on. This is the least common, but potentially most severe adverse reaction to NRL (because it could be the first sign of anaphylaxis).
  • Allergic Contact Dermatitis – is a delayed hypersensitivity and usually manifests as chronic hand Eczema. This is a common form of Occupational Dermatitis. Many patients start off with Atopic Hand Eczema and start wearing latex gloves to protect their hands and later develop a secondary rubber contact dermatitis, as it is easier to sensitize already damaged skin.
  • Irritant non-allergic Contact Dermatitis – can occur from the increased sweating that occurs from wearing gloves. This is the most common problem caused by wearing latex gloves.

Systemic Reactions

  • Rhino conjunctivitis – this occurs mainly with the use of powdered gloves, and is due to airborne latex attached to powder.
  • Asthma
  • Intraoperative Anaphylaxis
  • Unexplained Anaphylaxis

Food Allergy & Latex Allergy

A few individuals with NRL allergy are also allergic to certain fruits, most commonly bananas, avocado, or kiwi fruit. The cross-reactivity is due to proteins called "chitinases" that are present in both NRL and these fruits. Other foods reported to cross-react with NRL include apricot, chestnut, grape, passion fruit, and pineapple.

  • In some individuals with both NRL and food allergies, the NRL allergy occurred first, whereas in other individuals, the food allergy occurred first.
  • There is no connection between food allergy and either irritant dermatitis or contact dermatitis induced by NRL.
  • NRL allergy is caused by dipped rubber products (latex gloves, balloons, condoms, etc) rather than by dry processed or injection-molded rubber products (vehicle tyres, baby pacifiers, rubber stoppers, etc.), so exposure to these latter products rarely causes problems.
  • Even for persons allergic to banana, avocado, or kiwi fruit, exposure to rubber products made from synthetic rubber poses no risk.

Management of Latex Allergy

Hypoallergenic gloves have been introduced in response to the growing problems of occupationally acquired hand dermatitis. Such labeling can, however, be misleading and some gloves contain measurable allergen levels. Hypoallergenic gloves containing natural rubber latex, will not address the problem of individuals suffering from latex allergy and their inappropriate use may provoke a potential life threatening reaction. Regulatory authorities must ensure that manufacturers provide adequate labeling for gloves, with the appropriate warning about their allergen content. Dental care workers must become more knowledgeable about gloves and their allergen content. They should also have measures outlined for handling "latex sensitized" individuals when they show up in their surgery.

If the sensitivity is severe then individuals should wear a Medic-Alert Bracelet stating that they have latex anaphylaxis and must avoid all contact with latex.

As many medical personnel are unfamiliar with the problem of latex sensitivity and its potential severity, it can be invaluable for patients to carry information enlarging on the problem and highlighting sources of possible contact with latex rubber in the hospital environment.

The American College of Allergy and Immunology has put forth the following recommendations:

  • Just as patients are routinely asked preoperatively about allergy to medications prior to treatment, a careful history should be obtained from every patient prior to any procedure involving contact with latex. Any patient, who has a history of rash, itching, hives, rhinitis, swelling, or eye irritation or asthmatic symptoms after touching a balloon, condom, rubber glove or any latex containing object is at risk for anaphylaxis. Previous medical history, of unexplained allergic or anaphylactic reactions during a medical procedure, may indicate sensitization.
  • Health care providers or other workers who give a history of only mild latex-glove eczema (dermatitis) rarely have anaphylactic events. However a history of work-related conjunctivitis, rhinitis, asthma or urticaria may indicate allergic sensitization and increased risk for more severe reactions in the future.
  • The utility of screening tests for predicting anaphylaxis should be considered. Skin prick test can be done but this should be carried out in a setting where resuscitation can be carried out, as anaphylaxis can occur from skin testing. A blood (RAST) test can also be helpful in the diagnosis.

Latex Allergy Links
http://latexallergylinks.tripod.com/

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