Have you noticed that airlines no longer give out peanuts as inflight snacks? One of the reasons for this is the increase in food allergies, some of them quite serious and even life-threatening.
A research study in the January issue of the Journal of Allergy and Clinical Immunology found that 95 per cent of food allergy fatalities were as a result of eating peanuts or other nuts.
Dr Hugh Sampson and his colleagues at the Institute of Food Allergy, part of the Mount Sinai School of Medicine in New York, analysed data on 32 Americans who died as a result of an allergic reaction to food. Most of the fatal reactions occurred in adolescents and young adults. A key finding was that most of them died while eating away from home. And although most people knew of their allergies prior to the fatal incident, many of the 32 were not carrying the injectable adrenaline which had been prescribed to cover just such an eventuality.
This raises a question of public and indeed professional awareness of the condition and its recurring nature. It is not enough for health professionals to treat someone with a first mild allergic reaction and send them off with a warning about not eating the same food again. Patients need to be assessed by a specialist who will carry out further tests, educate them about food avoidance diets and teach them in detail how to use the injectable adrenaline pen.
Dr Joe Fitzgibbon, a Galway doctor who specialises in the treatment of allergies, says: "A number of unexpected, unexplained sudden deaths in this country may be due to clinically unrecognised fatal illness."
Echoing the findings of the US study, he is concerned that people with a history of known allergy are unwittingly put in danger when they eat out.
"I advise patients to be very careful about eating outside the home. Never put your life in the hands of a caterer," he says. "I would like to see the whole issue of food allergies addressed in training programmes in the hotel and catering industry." He believes that waiters would benefit by understanding that some customers are not just being awkward but have a genuine medical problem when they question the contents of a dish. And chefs would learn that using the same knife or chopping-board to slice a melon immediately after it has been used for a kiwi fruit could cause a fatal allergic reaction in a customer who has been very careful not to order kiwi in the first place.
While peanuts and tree nuts top the list of allergens, cow's milk, fish, shellfish and eggs can also trigger an allergic reaction in some people. Kiwi fruit, bananas and sesame seeds are other established causes.
Allergic food reactions cover a spectrum of symptoms, ranging from a mild nettle-type rash - urticaria - to a very severe reaction with constriction of the chest, swelling of the tongue and throat and collapse of the cardio-vascular system.
A recent study in the Lancet advocates the use of a tiered approach to patients with anaphylaxis (hypersensitive reaction). People with "mild" allergies should be given antihistamine tablets to take in the event of further attacks; those with "moderate disease" should be prescribed inhaled adrenaline; and patients at the severe end of the spectrum should be given the "Anapen", an intra-muscular injection of adrenaline in pen form.
However, this research is criticised by a number of experts who point to the fact that up to 44 per cent of people with a history of mild food allergy may unexpectedly develop severe and potentially life-threatening allergic reactions.
Dr Fitzgibbon agrees. "We can't predict who will subsequently get a severe allergic reaction. If in doubt, the patient must use the pen," he says. The fact is, however, that inhaled adrenaline is not available in the Republic.
WHEN somebody has a reaction, the possibility of death is related to three things: the speed of symptom onset, the severity of symptoms, and whether or not the sufferer gets adrenaline within the first 30 minutes.
Having bought time with the self-administered adrenaline, the patient must get further medical treatment. In about 10 per cent of cases, a second severe reaction can occur six to eight hours after the first.
In a welcome initiative, the Western Health Board plans to supply anaphylaxis treatment packs to family doctors in May. As well as the adrenaline injections, they will include information designed to improve professional awareness of severe allergic reactions and their management.
Is it possible to cause more harm than good by inadvertently using an Anapen? Well, the worst that can happen is that a patient gets a severe headache and a racing heart. The advice from Dr Fitzgibbon is straightforward: "Shoot first and ask questions later."
Further information: Could it be an Allergy? by Dr Joe Fitzgibbon (Newleaf, Gill & Macmillan); Irish Anaphylaxis Campaign, PO Box 4373, Dublin 18.
Dr Muiris Houston, Medical Correspondent, can be contacted at mhouston@irish-times.ie or messages can be left at tel: 01-6707711, ext 8511. Dr Houston regrets he cannot reply to individual medical problems.