Introduction
Demographics
Causes
Clinical features
Variation in skin types
Complications
Diagnosis
Differential diagnoses
Treatment
Prevention
Outcome
Over 90% of natural rubber comes from the latex, or the milky sap, of the rubber tree, Hevea brasiliensis. Latex can cause reactions ranging from rashes to anaphylaxis.
Latex is ubiquitous in healthcare. It is most commonly used in medical and surgical gloves and also in catheters, balloons, IV tubing, respirators, other medical and dental devices, and condoms. Latex allergy is among the most common causes of anaphylaxis in the operating room.
Natural latex rubber is also found in other products such as toys, erasers, sports equipment, clothing, and elastic bands.
Anyone who is exposed to latex is at risk of becoming sensitised; fortunately, the majority of people do not.
Risk factors include:
The prevalence of latex allergy in the general population has been estimated at approximately 4.3%. However, in high-risk populations increased prevalence has been reported eg, around 9.7–12.4% in healthcare workers, and up to 40–65% in paediatric spina bifida patients.
For reasons not yet understood, some people can become allergic to certain constituents of the latex molecule. Once allergic, sensitivity remains lifelong. There are hundreds of different chemicals within natural latex, but 15 are thought to be responsible for most reactions (Hev b1 to Hev b15).
Latex reactions can be triggered by several modes of exposure, including:
The surge in demand for latex gloves in the 1980s, driven by new recommendations for use amid the HIV epidemic, led to shortcuts in product cleansing during manufacturing, resulting in gloves with higher allergenic potential.
A true latex allergy will result in a type I hypersensitivity reaction mediated by IgE antibodies that bind to the allergenic latex proteins. The binding triggers mast cells and basophils to release histamine, leukotrienes, prostaglandins, and kinins, resulting in an immune response.
During latex processing, chemical antioxidants are added, which can also cause delayed type IV hypersensitivity reactions (such as thurams, and carbamates). True type IV allergy to latex is reported but much less common than type I reactions
See also: Allergies explained.
The common manifestations of latex sensitivity are:
Immediate-type hypersensitivity requires previous sensitisation and is the most potentially dangerous reaction to latex. Clinical presentations vary but may include contact urticaria, coryza, conjunctivitis, stinging or burning, asthma, or (with mucosal or parenteral exposure) anaphylaxis. A common cause for asthmatic reactions is powdered gloves due to starch powder picking up latex proteins.
Contact urticaria usually presents with pruritus (itching) and swelling of the skin at the site of contact with latex, for example on the hands from wearing gloves or on the genitals from condom use. Symptoms usually start within 5–15 minutes after contact with the latex product, although onset can be delayed for several hours. Symptoms may continue for hours to days after the latex contact has ceased.
Contact dermatitis from latex may take several days to appear. It presents with an itchy, scaly rash, and there may be small blisters if the reaction is acute. The rash usually lasts several days to weeks, or longer if exposure to latex continues.
Contact dermatitis is not generally caused by sensitivity to latex proteins but rather to the chemicals used in the manufacture of the latex product, including antioxidants and rubber accelerators thiuram, carbamates, and mercaptobenzothiazole.
It is currently not known if latex allergy is more prevalent in people with lighter or darker skin types.
Allergic contact dermatitis can appear red in some skin types. In darker skin, erythema may be less evident, and affected skin may appear purple or darker than the surrounding skin instead.
Severe clinical manifestations include bronchospasm, hypotension, cardiorespiratory collapse, and shock. Anaphylactic shock is potentially fatal and occurs most commonly in an intraoperative context. Patients who have had frequent exposure to latex have a higher risk of sensitisation and anaphylaxis.
In most cases, a diagnosis of latex allergy can be made from an accurate history and clinical examination.
History-taking should include questions about:
There are a number of tests that can confirm latex sensitivity, including:
Ensure patients are informed when they have had a suspected latex-related allergic reaction, and recommend referral for consideration of latex allergy testing.
Irritant contact dermatitis can present similarly to a latex allergy, although it is actually a non-immunologic reaction where friction or contact with chemicals results in irritated skin. When immediate reactions occur in settings where latex exposure has occurred, consider that it may be an allergen other than latex that is the responsible culprit.
Healthcare services should offer a latex-safe environment to patients with known latex allergy.
Latex allergy should be added in patients' clinical notes and a medical alert bracelet may be recommended.
Each ward/department should consider who is likely to be high risk and develop an emergency kit of latex-free products for use. The equipment required will vary and will need to be identified by the clinical area.
Employers should be aware of the latex allergy so that necessary measures can be taken.
Avoid contact with latex gloves and products.
Other suggested measures
If a reaction occurs, identify and remove the source of the latex exposure.
Management of exposed and symptomatic individuals depends on the type of reaction, and may involve:
Workers in high-risk occupations such as healthcare can help prevent latex sensitivity by:
For those sensitised to latex, education is crucial for the prevention and early management of allergic reactions, including:
There is currently no cure for latex allergy. Education on products containing latex and safe alternatives is important for avoidance. It is also essential for patients with a latex allergy to let healthcare providers know, to enable provision of a latex-safe environment.
