Natural latex is a particular kind of rubber that has been manufactured from the sap of the rubber tree. Latex is used in the manufacture of a large number of consumer products.
What is latex allergy?
The protein in latex rubber causes allergic reactions in some people. The thin, stretchy rubber in gloves, condoms and balloons is high in this protein, which means these items cause more reactions than products made of hard rubber, such as tyres.
Products made from rubber latex usually contain a number of chemicals, and some people are not so much allergic to the rubber but the synthetic chemicals found in it. Because people can be allergic to different natural or synthetic materials in rubber, we speak of latex allergies generally, but those affected should try to identify the specific components involved in their reactions.
When a latex-allergic person touches rubber, his or her body thinks the rubber is trying to attack it and perceives it as foreign. The immune system launches a counter-attack that can cause a host of unpleasant and, in some cases, life-threatening symptoms.
Who is at risk?
Latex products are everywhere, and anyone can become allergic to it. Healthcare workers who frequently use latex gloves and constantly touch products containing latex are at higher risk than average, as are people with medical conditions that require frequent procedures or surgery.
Those who work in manufacturing of latex products are also at greater risk, as well as children with congenital neurological abnormalities such as spina bifida and people with bladder problems. It is estimated that up to 65 per cent of American children with spina bifida have latex allergy.
Other risks pinpointed by medical experts are less defined but include a history of hay fever, a history of food allergies to tropical fruits, hazelnuts, chestnuts or stone fruits, or hand dermatitis that is severe.
What are the symptoms?
Latex allergy often begins with a rash on the hands following use of rubber gloves, but can also manifest itself through respiratory distress, eczema or oedema. Other signs include hay fever, itchy and swollen eyes, a runny nose and sneezing following latex exposure. Some patients can develop asthma symptoms such as chest tightness, wheezing, coughing and shortness of breath.
Other symptoms can include rashes, swelling, facial flushing or hives, rapid breathing, anxiety and confusion, feeling faint or shock.
Some people who work in latex gloves get bumps, sores, cracks or red raised areas on their hands over days or weeks. These reactions can be caused from frequent hand washing, antiseptics, constant covering of the hands or chemicals, and are not related to latex allergy.
Can it be fatal?
While it is very uncommon, some individuals can suffer a serious allergic reaction called anaphylaxis when they come into contact with latex rubber. This can occur in the mouth when blowing up a balloon, undergoing dental surgery, using a condom, during a rectal or colon examination or via catheterisation.
Anaphylactic shock occurs within minutes and is characterised by generalised hives, breathing difficulties and low blood pressure.
Can food allergies be involved?
Yes, they can. Many of the proteins that cause latex allergy are found in fruit, vegetables, nuts and cereals. This phenomenon is known as 'cross-reactivity'. Kiwifruit, passionfruit, cherries, potatoes, paw-paw, papaya, banana, avocado, fig, peaches, nectarines, plums, tomatoes, celery and chestnuts are all foods that can sometimes be linked with latex allergy. If you have a latex allergy, you don't have to avoid all of the foods that can potentially cross-react with latex - only those cause an allergic reaction for you.
Dr Vincent St Aubyn Crump, from Auckland Allergy Clinic gives a further insight into some of the idiosyncrasies of fruit, latex and birch pollen cross-reactions.
In my practice, I have seen several patients with kiwifruit allergy. All the patients I've seen with kiwifruit allergy were allergic to birch pollen and get birch pollen hay fever. All the patients I see have a positive skin test to the fresh kiwifruit. The commercial extracts for fruits are renowned for being unreliable (giving false negative results) because of the short shelf life.
About half of the patients I see with kiwifruit allergy have systemic reactions (anaphylaxis) to kiwifruit and most of these will get oral allergy syndrome (itching and swelling in the mouth and throat). The other half will get the oral allergy syndrome only. A few of them will be positive to latex, but only one of my patients, from memory, has clinical latex allergy.
I tell all my patients with kiwifruit fruit allergy to reduce latex exposure, especially if they are atopic or allergic, as this makes them a high risk for latex allergy.
I offer desensitisation to birch to all of them, as the literature shows improvement in kiwifruit allergy after immunotherapy to birch. I have not rechallenged any of my patients, so can't comment on the improvement of kiwifruit allergy after this desensitisation.
Often these patients with kiwifruit allergy are allergic to apple and hazelnut as well.
Am I likely to grow out of it?
No treatment is yet available to 'cure' a latex allergy. So far the best treatment is to avoid exposure to latex, in tandem with using medications to temporarily alleviate symptoms.Latex allergies can, however, get worse. There is evidence to suggest that the more you are exposed, the more allergic you become.
How is latex allergy diagnosed?
Swelling and itching after medical examinations, contact with rubber gloves, mouth discomfort after blowing up a balloon or undergoing a dental examination are all signs of latex allergy. Itching in the mouth and throat after eating banana, chestnuts or avocados is sometimes a signal that a latex allergy exists.
See a doctor if you suspect latex allergy, preferably one with experience in allergies. Your doctor will take a detailed history, and may confirm the diagnosis with a blood test. Skin testing is another option, but because it involves a small exposure to latex, most doctors prefer the risk-free blood test as a first step.
What about other warning signs?
Other warning signs include hives under rubber gloves, hand dermatitis related to gloves, allergic conjunctivitis after rubbing eyes with a recently degloved hand, vaginal burning after pelvic exams or contact with condom, and occupational asthma.
What precautions should latex-allergic people take?
No latex is allowed in the children's wards of many hospitals. Some will let you decorate a waiting room or the "Day room", but none of the patient's rooms. And no balloons at all in ICU'S. Latex balloons are the leading cause of paediatric choking deaths in the US. An increasing number of patients and staff have developed an allergy to latex. Symptoms of latex allergy may be mild or severe and range from hives and swelling to respiratory failure. Mylar/Foil balloons will only be accepted in many hospitals.