Latex allergy

Latex allergy is a medical term encompassing a range of allergic reactions to the proteins present in natural rubber latex. Latex allergy generally develops after repeated exposure to products containing natural rubber latex. When latex-containing medical devices or supplies come in contact with mucous membranes, the membranes may absorb latex proteins. The immune system of some susceptible individuals produces antibodies that react immunologically with these antigenic proteins. As many items contain or are made from natural rubber, including shoe soles, pen grips, hot water bottles, elastic bands, rubber gloves, condoms, baby-bottle nipples, and balloons, there are many possible routes of exposure that may trigger a reaction. People with latex allergies may also have or develop allergic reactions to some fruits, such as bananas.
Types.
Natural rubber latex is known to cause allergic reactions of Type I (e.g. anaphylaxis) and Type IV (e.g. allergic contact dermatitis) as well as non-allergic irritant contact dermatitis.
Type I.
The most serious and rare form of latex allergy, Type I hypersensitivity can cause an immediate and potentially 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 I natural rubber latex allergy is an IgE (immune) mediated reaction to proteins found in the "Hevea brasiliensis" tree, a type of rubber tree.
Testing for type I natural rubber latex allergy is through blood testing to determine if the patient is producing IgE antibodies to latex proteins.
Anaphylactic shock can be provoked in allergic persons by the "previous" use of latex in an area: latex is typically powdered to prevent sticking, latex proteins become attached to the particles of powder, and the powder becomes airborne when the latex item is used, triggering potentially life-threatening Type I reactions when the latex-contaminated powder is inhaled by susceptible persons.
In radiological units latex allergy may mimic contrast medium allergy
Type IV (allergic contact dermatitis).
Type IV allergy, also known as allergic contact dermatitis, involves a delayed skin rash that is similar to poison ivy with blistering and oozing of the skin ("see urushiol-induced contact dermatitis"). It can be diagnosed through a positive skin patch test, although a negative test does not rule out a latex allergy.
Severe irritation takes place if a latex catheter is inserted in the urinary tract of a person allergic to latex. That is especially severe in case of a radical prostatectomy due to the open wound there and the exposure lasting e.g. two weeks. Intense pain may indicate such situation.
Irritant contact dermatitis.
Natural rubber latex can also cause irritant contact dermatitis, a less severe form of reaction that does not involve the immune system. Contact dermatitis causes dry, itchy, irritated areas on the skin, most often on the hands. Latex-glove induced dermatitis increases the chance of hospital-acquired infections, including blood-borne infections, being transmitted.
Latex-fruit syndrome.
People who have latex allergy also may have or develop an allergic response to some plants and/or products of these plants such as fruits. This is known as the "latex-fruit syndrome". Fruits (and seeds) involved in this syndrome include banana, avocado, chestnut, kiwifruit, mango, passionfruit, fig, strawberry, papaya, apple, melon, celery, potato, tomato, carrot, and soy. The proteins in these are similar to the protein in latex.
Hevein-like protein domains are a possible cause for allergen cross-reactivity between latex and banana or fruits in general.
Natural rubber latex contains several conformational epitopes located on several enzymes such as "Hev b 1", "Hev b 2", "Hev b 4", "Hev b 5" and "Hev b 6.02".
FITkit is a latex allergen testing method for quantification of the major natural rubber latex (NRL) specific allergens: Hev b 1, Hev b 3, Hev b 5, and Hev b 6.02.
Epidemiology.
Estimates of latex sensitivity in the general population range from 0.8% to 8.2%.
Alternatives.
For some people, the sensitivity is so extreme that replacement of latex products with products made from alternative materials may still result in a reaction if the products are manufactured in the same facility as the latex-containing products, due to trace quantities of natural rubber latex on the non-latex products.