Three types of reaction to latex may be seen:

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Non-allergic irritation, caused by chemicals used in the manufacturing process, which is localised and usually reversible.

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Delayed hypersensitivity (Type IV, T-cell mediated) occurring a few hours to a few days after contact.  This is the most common type of latex allergy, is usually against chemicals added to the latex, and is localised.

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Immediate hypersensitivity (Type I, IgE mediated) is an allergy to natural latex rubber proteins. It occurs within minutes of contact, it may be localised but may also cause a systemic reaction, and potentially anaphylactic shock. 

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A crude estimate is that 1.5 to 2 million people in the UK may be at risk.  In the general population, prevalence is probably less than 1%.  Suggested prevalence varies widely between different studies.

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Risk increases to about 7% in individuals with a history of allergies, more if fruit allergies - especially banana, avocado, chestnut, and kiwi - are present.

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A history of exposure to latex gives a risk of allergy in the range 3 - 17%.  This includes people involved in the manufacture or use of latex.  Healthcare workers are a large group who, with the increase in ‘universal precautions’, have an increased risk.  Patients with history of repeated surgery are high risk; the highest rates quoted are 18 - 68% in those with spina bifida.

Sensitisation may be from contact, or inhalation of latex proteins on glove powder, and different supplies of latex vary in their protein content.  Combinations of risk factors - e.g. an atopic healthcare worker - increase the risk.

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A full medical history is the most important tool in screening for latex allergy.  If this shows an increased risk, allergen testing should be considered.

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Serum specific allergen assays (“RAST”) are safe, and current assays are sensitive.  However, turnaround times are about two weeks, and patients may demonstrate antibodies that do not react in vivo.

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Skin prick testing (using commercial allergen preparations, or pricking through a piece of latex glove) gives an immediate result.  It carries a theoretical risk of anaphylaxis, so latex-free resuscitation equipment must be available.  It is less suitable for patients with skin problems, or who are on medication that may suppress the immune reaction. 

Patch testing will detect delayed (Type IV) reactions.

Provocation tests have been used - the patient wears one latex glove and one vinyl glove for 15 minutes - again there is a theoretical risk of anaphylaxis.

1.

American Academy of Allergy, Asthma and Immunology: www.theallergyreport.org/reportindex.html

2.

American Association of Nurse Anesthetists: www.aana.com/crna/prof/latex.asp

3.

Bandolier EBM: www.jr2.ox.ac.uk/bandolier/bandopubs/NHSSlatex.html

Bowyer R. (1999).  Latex allergy: how to identify it and the people at risk.  Journal of Clinical Nursing 8(2): 144-149