Dissolving wafer to stop severe allergic reaction

A‘wafer’ that dissolves in the mouth in seconds could stop life-threatening allergic reactions in their tracks. The transparent wafer — about the size of a postage stamp and strawberry-flavoured — is placed under the tongue at the first sign of a dangerous allergic reaction (called anaphylaxis), such as difficulty breathing, a rapid heart rate, or swelling in the throat and mouth.

Its gel layers then rapidly dissolve to release a dose of the hormone adrenaline — the main emergency treatment for anaphylaxis. This is quickly absorbed by the tiny blood vessels under the tongue and circulates around the body in minutes, dampening down the potentially lethal allergic response.

Currently, adrenaline is given as an injection — usually into the thigh — using a disposable auto-injector device, such as an epiPen.

an estimated 250,000 people with allergies are prescribed the devices on the NHS. Many are advised to carry two autoinjectors at all times in case a severe reaction is triggered and the first jab does not reduce the symptoms sufficiently. But while the pens are very effective at halting anaphylaxis, there are some problems with their use.

Many patients are reluctant to use them because they are frightened of needles; others may leave them at home when they go out as the auto-injectors are bulky.

Meanwhile, studies suggest two-thirds of people prescribed auto-injectors do not use the devices properly.

with an epiPen, for example, it must be firmly pushed into the fleshy part of the thigh and held in place for around five seconds to ensure all the dose is administered. But only 30 per cent of patients knew how to use their injectors correctly, a 2017 study (on adults and children) by doctors at the royal alexandra Children’s Hospital in Brighton found.

The wafer, developed by U.S. drug firm aquestive Therapeutics, could be the solution.

Not only is it easier to use, it does away with the need for injections and is small enough for patients to discreetly carry several wafers at all times.

at least two million people in the UK have food allergies that put them at risk of anaphylaxis. when they come into contact with the offending items, the immune system releases chemicals designed to vanquish what it thinks is a dangerous invader.

It’s this rush of chemicals that triggers the symptoms of an allergic reaction, often within seconds of consumption.

These range from an itchy mouth, nose or ears to life-threatening anaphylactic shock, where the airways narrow, blood pressure plummets and major organs shut down.

as with auto-injectors, the wafers will come in standard doses of 0.3mg of adrenaline for adults and 0.15mg for children.

Now a trial is under way in the U.S., involving 28 people with severe allergies, to see if the promising results can be replicated in humans.

Dr Paul Turner, a specialist in paediatric allergies at St Mary’s Hospital, London, says: ‘This is very exciting.

‘Some patients struggle with using auto-injectors correctly. an auto-injector can also only be used once, and patients often need more than one dose of adrenaline. The wafer would allow people to tailor the amount of adrenaline to what their body needs.’