Latex allergy

Latex allergy is a medical term encompassing a range of allergic reactions to natural rubber latex.

Type 1
The most serious and rare form, type 1 is an immediate and life-threatening reaction, not unlike the severe reaction some people have to bee stings. Such reactions account for a significant proportion of perioperative anaphylactic reaction, especially in children with myelomeningocele.

Type 1 hypersensitivity is an allergic reaction provoked by reexposure to a specific type of antigen referred to as an allergen. Exposure may be by ingestion, inhalation, injection, or direct contact. The difference between a normal immune response and a type I hypersensitive response is that plasma cells secrete IgE. This class of antibodies binds to Fc receptors on the surface of tissue mast cells and blood basophils. Mast cells and basophils coated by IgE are "sensitized." Later exposure to the same allergen, cross-links the bound IgE on sensitized cells resulting in degranulation and the secretion of pharmacologically active mediators such as histamine, leukotriene, and prostaglandin that act on the surrounding tissues. The principle effects of these products are vasodilation and smooth-muscle contraction.

The reaction may be either local or systemic. Symptoms vary from mild irritation to sudden death from anaphylactic shock. Treatment usually involves epinephrine, antihistamines, and corticosteroids.

Some examples:

* Allergic asthma
* Allergic conjunctivitis
* Allergic rhinitis ("hay fever")
* Anaphylaxis
* Angioedema
* Atopic dermatitis (eczema)
* Urticaria (hives)

Type 4
Also known as allergic contact dermatitis. This involves a delayed skin rash that is similar to poison ivy with blistering and oozing of the skin. This type is caused by chemicals used in the processing of rubber products.
Irritant contact dermatitis
The most common type of reaction. This causes dry, itchy, irritated areas on the skin, most often on the hands. It can be caused by the irritation of using gloves, or it can also be caused by exposure to other workplace products. Frequent washing of the hands, incomplete drying, exposure to hand sanitizers, and the talc-like powder coatings (zinc oxide, etc) used with gloves can aggravate symptoms. Irritant contact dermatitis is not a true allergy.

Type 4 hypersensitivity is often called delayed type as the reaction takes two to three days to develop. Unlike the other types, it is not antibody mediated but rather is a type of cell-mediated response.

CD8 cytotoxic T cells and CD4 helper T cells recognise antigen in a complex with either type 1 or 2 major histocompatibility complex. The antigen-presenting cells in this case are macrophages and they release interleukin 1, which stimulates the proliferation of further CD4 cells. These cells release interleukin 2 and interferon gamma, further inducing the release of other Type 1 cytokines, thus mediating the immune response. Activated CD8 cells destroy target cells on contact while activated macrophages produce hydrolytic enzymes and, on presentation with certain intracellular pathogens, transform into multinucleated giant cells.

Some clinical examples:

* Contact dermatitis (poison ivy rash, for example)
* Temporal arteritis
* Symptoms of leprosy
* Symptoms of tuberculosis
* Transplant rejection
* Coeliac disease


Testing for type 1 natural rubber latex allergy is through blood testing, such as RAST (radioallergosorbent test) identifies what types of IgE proteins trigger allergic reactions. While the standard for allergen testing is the skin prick test, there is no approved skin testing reagent for latex in the United States at this time. Some other countries do have approved skin testing reagents for natural rubber latex. Some people who are allergic to latex are also allergic to clothes, shoes and other things that contain natural rubber latex - for example elastic bands, rubber gloves, condoms, pacifiers and baby-bottle nipples, balloons, cars and clothing containing natural rubber based elastic. Synthetic elastic such as elastane or neoprene do not contain the proteins that trigger type 1 reactions. Type 1 natural rubber latex allergy is caused from IgE (immune) mediated reactions to proteins found in the hevea brasiliensis tree, a type of rubber tree. Synthetic latex products do not contain the proteins from the hevea brasiliensis tree and will not cause this type of reaction.

Type 4 reactions are caused by the chemicals used to process the rubber. Patch testing needs to be done to verify which type of chemical triggers the reaction. Once the chemical is identified, then the person can choose products that are not processed with that chemical. Both natural rubber and synthetic rubber products may cause type 4 reactions.

Those at greatest risk

* Children with myelomeningocele (also known as Spina bifida). Between 40% to 100% will have a reaction.
* Industrial rubber workers, exposed for long periods to high amounts of latex. About 10% have an allergic reaction.
* Healthcare workers. Given the ubiquitous use of latex products in health care settings, management of latex allergy presents significant health organizational problems. Latex allergies are becoming more common among doctors, as they have regular and prolonged exposure to latex, mostly examination gloves. Between about 4% to 15% of healthcare workers have a reaction, although this is usually Irritant Contact Dermatitis, rather than an allergy.
* People who have had multiple surgical procedures, especially in childhood.

Estimates of latex sensitivity in the general population range from 0.8% to 6.5%, although not all will ever develop a noticeable allergic reaction.[citation needed]

Latex and foods

A latex allergy can also cause further reactions, to food items from the latex plant groups - banana, avocado, chestnut, strawberry, and kiwifruit. The Asthma and Allergy Foundation of America estimates that nearly 6 percent of the pediatric and adult population has some type of food allergy and up to 4 percent have an allergy to latex.[1] It can also cause reactions from foods touched by latex products in the most severe cases. There are some known cases of latex allergies being provoked from genetically modified foods such as tomatoes with latex proteins.

It is also worth noting that some highly latex allergic individuals have had allergic reactions to foods that were handled or prepared by people wearing latex gloves.

GLOVE SELECTION CHART

GLOVE SELECTION CHART

The following guide is a general guide for glove selection in relation to chemicals handled. The information presented here is believed to be accurate; however, we cannot guarantee its accuracy. Many factors affect the breakthrough times of glove materials including, but not limited to:

1. Thickness of glove material
2. Concentration of the chemical worked with
3. Amount of chemical the glove comes in contact with
4. Length of time which the glove is exposed to the chemical
5. Temperature at which the work is done
6. Possibility of abrasion or puncture.

Some Common Sense Rules for Glove Use

Select gloves which are resistant to the chemicals you may be exposed to. Consult the relevant Material Safety Data Sheet (MSDS) which may recommend a particular glove material.
Select gloves of the correct size and fitting; gloves that are too small are uncomfortable and may tear whereas overlarge gloves may interfere with dexterity. In some cases, such as use of HF, it may be advisable to select gloves that can be removed very rapidly in an emergency.
Before use, check gloves (even new ones) for physical damage such as tears or pin holes and for previous chemical damage: this is especially important when dealing with dangerous materials such as HF.
When working, it may be advisable to wash the external surface of the gloves frequently with water.
Some gloves, especially lightweight disposables, may be flammable: keep hands well away from naked flames or other high temperature heat sources.
When removing gloves, do so in a way that avoids the contaminated exterior contacting the skin.
Wash hands after removing gloves.
Dispose of contaminated gloves properly.
Do not attempt to re-use disposable gloves.
Never wear possibly contaminated gloves outside of the laboratory or to handle telephones, computer keyboards, etc.
This information is provided as a guide to proper glove material selection. Glove performance varies between manufacturers, so always give yourself extra time and do not push glove strength to the estimated limits and consult a certified safety consultant when in doubt to make sure you have the right glove for your application.

Click HERE for the glove selection CHART.