SUMMER CAN be hell for those with hay fever, as they sneeze and sniff their way through the season. But a new pill made from grass pollen offers the promise of a future without symptoms for some sufferers, at least.
The pill works by encouraging an immunological tolerance to pollen, explains Stephen Durham, professor of allergy and respiratory medicine at the Royal Brompton Hospital and Imperial College, London.
Each tablet contains 30 times the amount of pollen that most sufferers receive each summer — the theory is that this helps to “desensitise” the immune system to grass pollen (it is the same principle for immunotherapy, in which the patient is given weekly desensitising injections to lessen the body’s allergic response to the allergen, Durham says).
In a trial involving 855 patients from five European countries and Canada, Durham and his colleagues found that patients given the pill eight weeks before the grass pollen season started had a 20 to 30 per cent reduction in symptoms (the results of the trial are due to be published in the BMJ later this year).
The main advantage of sublingual immunotherapy (so-called because the pill is placed under the tongue) is that it is easy to administer and safe, says Durham. Apparently, even with its high pollen content, the pill reduces the risk of a strong allergic reaction because the T-cells under the tongue do not interpret grass pollen as an enemy, unlike those in the nose, lungs and skin, which attack the pollen with histamine, causing an allergic reaction.
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Dr Glenis Scadding, a member of the research team and consultant in rhinology and allergy at the Royal National Throat, Nose and Ear Hospital, London says that classic immunotherapy for hay fever can have serious side-effects including anaphylaxis, and thus is reserved for those patients with severe symptoms that do not respond to pharmacotherapy such as nasal sprays.
“It can be administered only in a specialist allergy clinic where there is access to cardiorespiratory resuscitation due to the risk of a severe and life-threatening reaction,” she says. Sublingual immunotherapy does not have to be administered by an allergy specialist and can be taken safely in the home — therefore it may take pressure off overstretched allergists. “There are only 27 full-time allergists for the thousands of sufferers who need specialist care,” says Dr Scadding. “This treatment could have a dramatic impact on how they are treated and their quality of life.”
“There is no evidence yet to show whether the tablet has a long-lasting effect compared with the injection,” says Durham. “More research is needed to work out the optimum dose to induce a long-term response.”
The pill, which is manufactured by a Danish company, is likely to be available next year, and may help some of the ten million people in the UK who suffer from hay fever every year (about 95 per cent of hay fever sufferers are allergic to grass pollen).
However, it is hoped that the new immunotherapy pill can be adapted for all kinds of allergies, says Muriel Simmons, of the charity Allergy UK. “We are really looking forward to the time when it will become the standard treatment. It’s so much kinder to people than the more risky injections. If it works there is no doubt that it will be the way of the future.”
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Meanwhile, it is important that hay fever sufferers take their medication early enough for it to work. In trials of the new drug, patients took the tablet daily for four months, thus ensuring that the body was tolerant of pollen before the grass season — which runs from May to August — started. Those with hay fever can make their symptoms worse because they don’t take their conventional medicine in time. “They think it won’t happen again this year,” says Simmons, “but starting early can mean a summer free of hay fever completely.”
Allergy sufferers, however, have to deal not only with their own apathy but with changes in the pattern of allergic reaction. According to Durham, allergic reactions are getting earlier and earlier each year.
“Cross-reaction is beginning to become more common as well,” he says. “More than 25 per cent of patients with a birch-pollen allergy have itching in the mouth when they eat apples and stone fruits such as peaches. There is also itching and swelling of the lips, which is something that I haven’t seen before.”
It seems that birch pollen contains proteins called profilins that are also present in apples and stone fruits, so birch allergy cross-reacts and causes symptoms on contact with these (this does not happen, however, when the fruit is cooked).
E-mail Dr Thomas Stuttaford your questions on hay fever