Asthma, Hayfever, Eczema and Latex Allergy

Health professionals represent the largest risk group for latex allergy and the public health and occupational health implications for latex sensitive health professionals are serious. With the increase in hepatitis and AIDS, the use of latex containing rubber gloves and condoms has increased exponentially during the past 10 years. Millions of individuals are being exposed annually to latex gloves, condoms and other devices resulting in sensitization, which for some individuals could have a fatal outcome. Because of its international intrigue and seriousness and the increasing widespread increase in the use of latex containing products, one could well regard latex as the “allergen of the decade”.

FIGURE 1:

Latex Allergy: High Risk Groups

Theatre Staff Patients with repeated surgical procedures Dentists Rubber industry workers Paramedics

Theatre staff are particularly at risk. The frequency of latex allergy in surgeons has previously been found to be 7.4% and in theatre sisters 5.6% (3) and this prevalence is increasing latex sensitization in dental workers.

The group of patients with the highest risk are children with spina bifida or congenital urological
abnormalities, who are subjected to repeated surgical procedures. The risk of sensitization increases with each procedure. Patients who have barium enemas are particularly at risk, and are the group with the highest mortality, reported to the FDA (USA). Females and atopic individuals have an increased risk of sensitization.

Anaphylaxis has also been reported in condom users. Atopic children repeatedly blowing up balloons are at risk. Sensitized individuals are at particular risk if they undergo surgery, dental procedure (with gloves), rectal or vaginal examinations.

Individuals who are allergic to avocado, chestnuts or bananas also have an increased risk of latex allergy. Large surveys have not been conducted, but the prevalence of latex allergy in the general population is of the order of 0.1%.

Isoprene itself is not believed to be allergenic, but about 18 IgE binding proteins which are closely associated with the isoprene have been identified. These proteins range from 2.5 kilodaltons to high molecular weight proteins of 100 kilodaltons, and include rubber elongation factor, hevein and hevamine. Different patients react to different proteins in the latex sap.

Children appear to react to different proteins compared with adults. More research is required to characterize the different latex allergens, so that reliable and appropriate testing reagents can be formulated. The abovementioned proteins are responsible for Type I allergy. Gloves may also contain other allergens, e.g. ethylene oxide, casein and corn to which patients may react with immediate hypersensitivity.

A number of contact sensitizing allergens which cause delayed (Type IV) hypersensitivity are also incorporated into gloves during the manufacturing process. These include carbamates and thiurams which are used as accelerators and hardeners. “Allergy” to these agents has been known since the 1920’s. Patients sensitive to these agents develop a local contact dermatitis and do not get generalized and more life threatening responses as occurs with true Type I latex allergy.

There is a large variation in the quality of gloves on the market. Cheaper latex gloves have often undergone poor quality control and are harmful if used repeatedly. It is possible to measure the free latex in these gloves using immunoblotting or the LEAP assay (latex ELISA for extractable protein).

If powdered poor quality gloves are used in a hospital environment, the air will be contaminated with latex. Staff will inhale latex and be sensitized. One way to reduce exposure is to use non-powdered or non-latex gloves. Latex “examination gloves” generally have much more extractable protein than the non-powdered surgical gloves. Outside of the hospital environment individuals are also being sensitized to latex in other ways, e.g. regular condom use.

Type IV contact hypersensitivity reactions characteristically affect the glove exposed areas and consist of swelling, redness of the skin which may extend up the arm, pruiritis, cracking of the skin and delayed eczema 6-48 hours after exposure. These reactions are never systemic and can be controlled by the use of topical steroids initially and the avoidance of further exposure to the contact allergens. Contact allergens are identified by PATCH TESTS.

With Type I immediate hypersensitivity reactions to latex, urticaria is the most frequent manifestation and was present in 21/23 of the patients in the Groote Schuur Hospital study. Other manifestations include allergic rhinitis, asthma, angioedema, conjunctivitis and fatal or non-fatal anaphylaxis. Patients present with different clinical patterns (Fig 3).

FIGURE 3

IgE Mediated Latex Allergy Clinical Manifestations

• Contact Urticaria
• Generalized Urticaria
• Conjunctivitis
• Rhinitis
• Bronchospasm
• Anaphylaxis

Some patients go through a phase of contact urticaria before progressing onto systemic symptoms, while other patients behave unpredictably and may develop severe bronchospasm and/or anaphylaxis without previous cutaneous manifestations (Fig 4).

FIGURE 4

Reported Causes of Latex Associated Anaphylaxis

• Powdered examination gloves
• Surgeons gloves
• Barium enema catheters
• Condoms
• IV catheters
• Urological catheters
• Balloons

Patients who have rhinoconjunctivitis and asthma are exposed by inhalation which is enhanced by the use of powdered gloves. Although starch or talcum is inert, latex proteins readily become associated with powder and are thus airborne when the health practitioner removes the gloves.

The hands of glove users are also contaminated and they may sensitize their eyes and mouths when taking off gloves, if hands are not washed after removing the gloves. Similarly, they can transfer latex proteins to equipment, door knobs and eating utensils if hands are not washed after wearing latex gloves.

If hospital personnel who are sensitized become patients themselves, they are at particular risk for severe reactions (e.g. during vaginal, rectal or dental examinations).

For patients with symptoms and signs suggestive of immediate (Type I) reactions, a CAP RAST test for latex is the safest and simplest test. It is highly specific and has a sensitivity of 70-80%. If the CAP RAST is negative, IN VIVO testing should be performed, but only in an environment equipped to resuscitate patients should they have an adverse reaction. Skin prick tests can be performed, but reagents for skin prick tests are not freely available on the South African market. An in house skin prick extract can be made by incubating the finger of the latex glove overnight with saline and using the saline extract for a prick test. The sensitivity of such testing is greater than 60% depending on the quality of the glove used. The lower the quality the higher the sensitivity of the skin prick test.

There is great variability in the different commercial latex extracts available in France, Canada and Spain and none are registered in the USA. This is because it is not known, with certainty, which the most important latex allergens are for
inclusion in tests. Prick tests are therefore only conducted by specialists in emergency room settings because of a risk of anaphylaxis. A “user test” is also advocated for patients who have less severe manifestations.

In this test the patient wears either a finger of the glove or a whole latex or non-latex glove for 20 minutes to an hour and the hand is inspected for urticaria. Patients who are allergic to latex may also be allergic to bananas, avocados, chestnuts and kiwi fruit due to crossreacting elements in these fruits (Fig 5).

FIGURE 5

Allergens which Cross-react with Latex

• Bananas
• Avocados
• Chestnuts
• Kiwi fruit

FIGURE 6

Approach to Latex Allergy – Summary

1.	IDENTIFY HIGH RISK CASES

2. 	PERFORM TESTS:
		
	(a)	Laboratory CAP RAST

	(b)	Skin prick tests

	(c)	Glove use tests

3.	REMOVE FROM LATEX EXPOSURE

4.	MEDIC ALERT

5.	EDUCATE PATIENT

6.	ANTI HISTAMINE AND SELF INJECTABLE ADRENALINE

7.	INFORM FAMILY DOCTOR, DENTIST AND EMPLOYER

Patients clinically sensitive to latex who have confirmation of their sensitivity by CAP RAST or other tests, should be educated about all possible sources of latex exposure in the home, work and recreational situation. Possible sources of latex exposure are listed in Table I (4). All sensitized patients should wear a MEDIC ALERT DISC. An accurate clinical diagnosis documented with laboratory or in vitro tests is essential for the purposes of workers compensation.

Patients should be educated about the risks of hospitalization, medical examinations and visits to the dentist. Their primary practitioner, dentist and employer should be informed.

For patients with documented sensitivity, removal of the patient from a latex “contaminated” environment is essential. Thus, certain patients should no longer be permitted to work in theatre. Medical personnel requiring gloves should wear latex free gloves. Latex free gloves are available from Regent UK, Dalhausen, Vinyl Glove (Cologne), 4H Glove (Lynby, Denmark), Tactylon (Smart Practice, Phoenix), Neolon (Deseret Medical Inc) and Ansell Dermaprene (Ansell, America) (5).

It should be remembered that so called “hypoallergenic” gloves are not latex free. They may be free of Type IV sensitizers such as thiurams or carbamates, but invariably contain latex.

It has been found that in theatres where powdered gloves are used, the rate of latex sensitization is much higher. The use of non-powdered, high quality, low protein gloves (e.g. Regent Biogel) is therefore recommended. Although higher quality gloves are more expensive, they are safer and the reduction in staff morbidity and sensitization will be well worth the extra expense in the long run.

Prevention of exposure in hospital is a major exercise for health authorities. The American Academy of Allergy has published a position paper with useful guidelines for the management of latex sensitive patients (6). An environment free of latex is one in which no latex gloves are used by any personnel. In addition, there should be no latex accessories (catheters, adhesives, tourniquets or anaesthetic equipment) that come into direct contact with the patient. Procedures on patients with a history of latex allergy or spina bifida should be performed in an environment free of latex.

Although premedication with antihistamines and steroids is recommended for patients with radio contrast media sensitivity, it is currently not clear whether such premedication would prevent severe allergic reactions should they be inadvertently exposed to latex during anaesthesia. Dangers to latex sensitive patients extend post-operatively when they return to the wards, where they may inadvertently receive drugs through rubber stoppered vials, or may inadvertently be catheterized with latex catheters. A vigilant approach by the attending physician or surgeon is thus essential, to protect the patients from all possible sources of exposure to the allergen.

FIGURE 7

Public Health Implications

• – Develop a hospital policy
• – Staff and patient education
• – Screen high risk patients
• – Only use latex products with low extractable protein
• – Minimize exposure – use latex substitutes
• – Provide a diagnostic service
• – Consider workers compensation/disability
• – Calculate cost of acquired allergy
• – Be prepared for litigation
• – Consider vocational rehabilitation

The cost to the hospital and the patient of an acquired latex allergy is enormous. Health professionals who become sensitized to latex must be removed from further latex exposure. This may involve a career change (e.g. for theatre staff). Certain individuals (e.g. asthmatics) may have to be medically boarded. The provision of latex free operating environments is expensive. Workers with occupational asthma, due to latex exposure, who cannot be accommodated within their usual workplace may apply for workers compensation and could demand substantial financial settlements from their employers. Where the employer is unsympathetic, legal costs may also be incurred.

In countries such as Finland and Canada, claims for workers compensation for latex related illness are increasing at an alarming rate. At Groote Schuur Hospital patients have already been boarded because of exquisite sensitivity to latex.

In view of these implications, it is imperative that, as a primary measure, hospitals routinely use products (gloves in particular) which have low extractable latex proteins and are powder free, even if these are more expensive. High risk medical personnel should be screened and if sensitized, removed from further exposure. Evaluation and follow up of the patients, by an allergist, is essential. Preventive measures such as these have been introduced at the Mayo Clinic and have resulted in savings to the hospital and significantly reduced the rate of staff sensitization.

“Allergen of the decade” Who is at risk? What are the allergens? Why the recent increase? Clinical reactions? Investigation and diagnosis Management of latex sensitive patients Public Health Implication The future Other Latex Allergy Websites

“Allergen of the Decade”

Who is at risk?

Health professionals represent by far the largest group at risk of developing latex allergy (Fig 1).

FIGURE 1:

Latex Allergy: High Risk Groups

Theatre Staff Patients with repeated surgical procedures Dentists Rubber industry workers Paramedics

Theatre staff are particularly at risk. The frequency of latex allergy in surgeons has previously been found to be 7.4% and in theatre sisters 5.6% (3) and this prevalence is increasing latex sensitization in dental workers.

The group of patients with the highest risk are children with spina bifida or congenital urological
abnormalities, who are subjected to repeated surgical procedures. The risk of sensitization increases with each procedure. Patients who have barium enemas are particularly at risk, and are the group with the highest mortality, reported to the FDA (USA). Females and atopic individuals have an increased risk of sensitization.

Anaphylaxis has also been reported in condom users. Atopic children repeatedly blowing up balloons are at risk. Sensitized individuals are at particular risk if they undergo surgery, dental procedure (with gloves), rectal or vaginal examinations.

Individuals who are allergic to avocado, chestnuts or bananas also have an increased risk of latex allergy. Large surveys have not been conducted, but the prevalence of latex allergy in the general population is of the order of 0.1%.

What are the Allergens?

Why the recent increase?

Clinical Reactions

Investigation and Diagnosis

Management of Latex Sensitive Patients