1Overview

Natural rubber is taken from the Hevea brasiliensis tree and it takes the form of a milky aqueous substance. Rubber is extracted by making cuts on the bark of the tree.
Then, preservatives and stabilizers are added to prevent the sap from coagulating.
People have developed allergies to latex, which is a form of rubber.
The type IV hypersensitivity reaction to latex additives has been documented and is increasing with the use of latex gloves in health care settings.

The simplification of the manufacturing process and the substitution of talc powder with starch are other reasons why latex allergies are increasing. Latex allergy has become a major healthcare problem all over the world. The alarming increase in anaphylactic reactions due to latex during operations or radiological procedures has prompted the United States Food and Drug Administration in 1990 to publish recommendations on the issue. In addition, the protein content that was previously found in gloves was lowered to reduce the possibility of allergic reactions. These measures partly halted the problem. However, in developing countries, the incidence of latex allergic reactions is increasing due to the increased use of latex products.

Fourteen allergens found in latex have been identified. Due to the fact that latex originates in plants, it contains pan-allergens and constitutive allergens. The different allergens have the capacity to sensitize patients through a variety of routes of exposure. Clinical pictures may vary, but there is usually some overlap.

2Triggers and Symptoms

The myriad of symptoms associated with type I hypersensitivity reactions to latex varies greatly. These reactions vary depending on the route of exposure, individual factors, and the amount of allergen present.

Contact urticaria is the most common manifestation of latex allergies. It also usually precedes systemic manifestations. Eczema and xeroderma after using latex gloves are not specific to latex allergy, but urticaria is a more specific symptom. Contact with the mucosa, such as the eyes, induces angioedema or swelling around the eyes.

Latex is also the most common cause of urticaria due to occupational exposure.
Dermatitis of the hands may be due to irritants and may increase sensitization to latex. Urticarial lesions that are due to type I hypersensitivity reactions to latex may become chronic and this could proceed to become protein contact dermatitis. Clinically, protein contact dermatitis manifests as prolonged eczema with several episodes of recurrent attacks.

Allergic rhinitis and asthma are also commonly observed in people with latex allergies. Latex is considered to be an allergen associated with the workplace and is the cause of occupational asthma in affected professions.

Systemic reactions may occur due to latex allergies. Anaphylactic reactions occur due to latex in the operating room. In this instance, cardiovascular collapse is the most common form of latex allergies in patients who have been anesthetized. In children, 27% of anaphylactic reactions following anesthesia is due to latex. The population at risk for developing anaphylactic reactions can be divided into individuals with a higher level of exposure, such as healthcare workers, or those with a genetic predisposition.

Irritant dermatitis is the most common primary presentation of latex allergy. It, however, is not an immediate or true allergic reaction since it does not involve the immune system. It results in skin that is dry, rough, and scaly. Sometimes, open sores can be observed.
It is made worse by sweating and friction, especially within rubber gloves.

Allergic contact dermatitis is a common reaction to latex that is immune in origin.
The symptoms look similar to irritant dermatitis, however, the cause is different. It is due to inflammatory reactions to the chemical added during the manufacturing process.

3Causes

Latex allergies are caused by immune reactions to latex proteins. Approximately 20% of latex proteins are allergenic and there are 250 types of latex proteins. A type I response to latex allergy is immediate, and typically occurs between 5-30 minutes after contact with latex. The symptoms of this are commonly swelling and redness, itching, and burning.
The symptoms can spread to other parts of the body and can be accompanied by conjunctivitis, bronchial obstruction, and rhinitis.

A type I allergic response is mediated through the action of IgE antibodies.
Hypersensitivity to latex due to IgE involves an early phase that develops rapidly and a late phase. In the early phase, latex antigens that are circulating cross-link with IgE receptors found on mast cells. This activates the cells to release histamine and other chemicals into the respiratory tract. The release of the mediators occurs within minutes of exposure to latex and correlates with the start of allergic symptoms. In the late phase, an influx of basophils, neutrophils, and eosinophils occur. This is followed by the production of factors that release histamine.Type IV hypersensitivity reactions to latex may also occur. This type of reaction is specific to the antigen, such as the chemical residues found on gloves during the manufacturing process. The response is delayed as opposed to immediate, and it occurs between 6-8 hours of initial contact. However, symptoms can last up to 4 days.

Type IV hypersensitivity reactions to latex may also occur. This type of reaction is specific to the antigen, such as the chemical residues found on gloves during the manufacturing process. The response is delayed as opposed to immediate, and it occurs between 6-8 hours of initial contact. However, symptoms can last up to 4 days.

The type IV response begins with the penetration of the skin by antigens, triggering the formation of T-cells that have become sensitized to the antigens. Repeated exposure to the antigen in susceptible individuals results in the re-activation of T-cells that have been sensitized and the production of an inflammatory response.

4Risk Factors

High-risk populations for latex allergies are those who are frequently exposed to latex, such as healthcare workers and factory workers. Patients who are undergoing multiple surgical procedures are also at risk, as are individuals with a history of atopy.
These populations have an increased risk for developing more severe allergic reactions compared to other populations.

In particular, individuals with congenital malformations of the central nervous system are especially at risk. This includes children with spina bifida. In these patients, the reported incidence of latex allergies is between 35-75%. These patients have an increased sensitization to latex proteins. They also have an increase in levels of specific and fully latex IgE starting from the perinatal period, which is associated with the occurrence of allergies in the future.

Another example is patients who are diagnosed with myelomeningocele. About 19.5% of this population have latex allergies. The most important risk factor for latex allergies, in these cases, is a history of at least 5 surgical interventions.

Intolerance to latex products, such as dental rubber dams, balloons, gloves, and preservatives is another risk factor. Allergy to fruits and anaphylaxis of unknown origin during surgery are also risk factors for the development or presence of latex allergies. Individuals who are allergic to specific fruits are at an increased risk for developing latex allergies. It was reported that between 21.2%-86% of these patients have a latex allergy. These fruits produce cross-reactions. Examples would be papayas, grapefruit, kiwi, avocado, banana, and almonds.

5Treatment

The treatment of latex allergies depends on avoidance. The treatment of the present reaction and avoidance of future reactions are the mainstays of treatment. Patients who have latex allergies should receive the standard treatment during, for instance, surgery, using latex-free materials and in an environment that is free of latex. In addition, patients must be reminded that they need to carry epinephrine injections at all times for emergency purposes. Epinephrine injectors are potentially life-saving during anaphylaxis. However, the importance of implementing measures to avoid future reactions is also important.

6Prevention

Patients must understand the importance of a correct diagnosis of latex allergies and know where latex may be present so that it can be avoided. This precaution is of special importance in the healthcare setting. Thus, if a patient is admitted to a hospital, the allergy to latex must be clearly stated in the clinical history, surgical reports, and nursing notes. Furthermore, patients are advised to wear a medical bracelet stating that they have a latex allergy.

The full avoidance of latex is often times considered to be impossible because of the widespread use of latex. However, full avoidance is not frequently necessary in most patients because the majority can tolerate rubber objects used in everyday life. Avoidance measures should also be implemented in patients who are suspected of having latex allergies.

There are alternatives to latex. The most important is the substitution of latex gloves, which are the main sources of latex allergens in the healthcare setting. However, not all alternatives to latex gloves are appropriate for all procedures carried out in the hospital.

The commonly used objects that may contain latex include adhesives, balloons, non-slip mats, condoms, contraceptive diaphragms, baby bottle nipples, pacifiers, shoes, gloves, diapers, elastic tissues, and elastic bands.

Patients should also be advised to avoid fruits that cross-react with latex allergens.

In addition, patients who are sensitive to latex should be properly assisted and screened before surgical procedures. In these cases, alternatives to latex gloves should be used. A number of hospital objects contain latex, such as catheters and syringes. Extra care must be taken to avoid an allergic reaction in patients with latex sensitivity.