Death on a plate

More people are suffering life-threatening reactions to food, and admissions to hospital have doubled in the past four years. Why? Judith Barrett investigates

Liz Orfao found out the hard way that her daughter Sofia, now 18 months, has a life-threatening allergy to cow's milk. "When Sofia was five and a half months old," explains Liz, "I mixed her baby rice with formula instead of breast milk. She gobbled up every last spoonful but then began to choke. Red circles developed around her eyes and red blotches appeared on her face. She became increasingly upset and then vomited. When we undressed her and saw the trunk of her body covered in hives we decided to go to the hospital. In the time it took us to get her into the car, she had stopped crying, her eyes were half closed, she was all floppy and seemed to be losing consciousness."

Liz Orfao found out the hard way that her daughter Sofia, now 18 months, has a life-threatening allergy to cow's milk. "When Sofia was five and a half months old," explains Liz, "I mixed her baby rice with formula instead of breast milk. She gobbled up every last spoonful but then began to choke. Red circles developed around her eyes and red blotches appeared on her face. She became increasingly upset and then vomited. When we undressed her and saw the trunk of her body covered in hives we decided to go to the hospital. In the time it took us to get her into the car, she had stopped crying, her eyes were half closed, she was all floppy and seemed to be losing consciousness."

Liz and her husband, Dominic Ciamfarani, already knew something about severe allergic reactions - "there was the time I nearly killed Dominic by accidentally giving him a bite of nut bar," says Liz - but they had never expected it to happen with baby formula. Both Dominic and Sofia are anaphylactic. That is, they are both at the most extreme end of the allergy spectrum where an allergic reaction can kill.

Peanuts are the most common food cause of anaphylaxis, but insect stings, drugs and latex can also cause a similar reaction. Other foods provoking an attack are tree nuts, seafood, egg - and, as in Sofia's case, milk products. Cow's milk allergy is common in infants and is in most cases mild, with 85-90 per cent outgrowing their allergy by age three. When it continues into adulthood, however, symptoms tend to be severe. Only time will tell into which group Sofia will fall.

Statistics on allergy generally are alarming. According to last summer's report from the Royal College of Physicians, Allergy the Unmet Need, the incidence of allergy in the UK has risen approximately threefold in the past 20 years, giving the UK one of the highest rates of allergic disease in the world. The report cites estimates that a third of the total UK population - approximately 18 million people - will develop an allergy at some time in their lives. Extreme allergic reactions - anaphylaxis - are increasing, too: hospital admissions due to anaphylaxis have increased sevenfold over the past decade and doubled over four years. Peanut allergy has trebled in incidence over four years and now affects one in 70 children in the UK. Yet only 10 years ago, this was a rare disorder.

But what makes some allergic reactions so severe? "This is what vast numbers of people are frantically trying to investigate," says John Warner, professor of child health at Southampton University, who specialises in allergic disorders.

Allergic reactions are the work of the immune system, which goes into overdrive to repel substances (proteins, except in the case of antibiotics) it wrongly perceives as a threat to the body. It counter-attacks by producing antibodies: the blood supply to the area increases, as well as other white blood cells and components of the immune system. The troublesome protein in milk is usually casein, but there are others. "It seems," says Professor Warner, "that the more proteins and components of the proteins of a given food to which an individual reacts, the greater the probability of a severe reaction."

This may be partly a consequence of the individual's genetic make-up and partly to do with how an individual first encountered the protein and became sensitive to it. "Perhaps," explains Professor Warner, "a baby is introduced to a new food at a time when its gut is inflamed - say, after a bout of gastroenteritis, and a protein is thus able to cross through the protective gut wall."

Other research by Dr Gideon Lack, consultant in paediatric allergy and immunology at St Mary's Hospital, Paddington, indicates that peanut oil contained in skin creams prescribed for the treatment of eczema may have been the "route of sensitisation" for many people allergic to peanuts. But, the scientists stress, "at the moment there are only hypotheses and not established facts."

While mild allergic reactions usually affect just one part of the body - the skin (eczema, or some sort of rash and itching), the gut (vomiting), tissue (swelling), or the lungs (asthma) - "the reaction becomes more dangerous when more than one organ is involved," says Dr Lack, and especially if it is the lungs or the heart.

So, the anaphylactic's mix of symptoms may include any or all of the above, as well as, possibly, a metallic taste in the mouth, swelling of the throat and tongue, difficulty in breathing and swallowing, increased heart rate and a sudden feeling of floppiness (due to a drop in blood pressure) - to the point of collapse and unconsciousness. "The most frightening thing is its unpredictability," says Dominic.

Asthma is a key risk factor for someone who has a food allergy: the reaction to the food may in turn trigger an asthma attack, so turning a mild reaction into the severe. "If a person has a food allergy and also suffers from asthma, which affects breathing, they should definitely carry an EpiPen," advises Dr Lack. The EpiPen (or Anapen - same drug, different mechanism) is an auto- injector of a life-saving shot of adrenalin, which shocks the body back into normal working. "Or if you have a severe reaction to only a small amount of the allergen, you should also keep an EpiPen with you at all times." And, preferably, two EpiPens - in case of one not working, and also because the reactions can be "bi-phasic", with a second wave occurring after the first has subsided.

Prevention of an attack in the first place is preferable, easier during the days of home-cooking than it is today with ready-meals and take-aways. Prevention now depends on the diligent reading of labels and quizzing of waiters and chefs, as well as EU directives to food manufacturers on the declaration of allergens and improved training and regulation within the catering industry. "Inevitably," says Professor Warner, "with our food so often prepared for us by other people, there is a higher risk of inadvertent exposure to allergens."

Diet is one of the possible explanations cited by Warner for why allergy generally is on the increase. "There is some evidence that eating less fresh fruit and fewer vegetables and polyunsaturated fatty acids has resulted in an increased susceptibility to allergy in general," he says, "as well as the possibility that young children are now more often exposed to potential allergens at a time when there is an increased risk of becoming sensitive to them" - for example, when the gut or skin is inflamed.

Scientists have also been delving deeper into the "hygiene hypothesis" - the idea that we are all too clean and free from infection for our good. Some scientists think that catching infections early in life may protect against allergy. However, according to Danish research reported this month by the British Medical Journal, which looked at 24,000 mother-child pairs and focused on eczema, with each infection the risk of developing an allergy increased. But those children who had more brothers and sisters, or who mixed a lot with other children, had pets or lived on farms, developed fewer allergies - because, the researchers thought, of the immune system's exposure to a greater number of micro-organisms.

"We still don't have the full answer," stresses Professor Warner. "Perhaps," he adds, "our capacity to develop allergy is important to fight parasites, part of a normal immune response to something like a tapeworm taking up residence inside us, to alert us to the fact that something is wrong." In the absence of such parasites, the immune system picks a fight elsewhere, seeing other proteins as the enemy.

Meanwhile, the NHS is struggling to cope with the increase in allergies. There are six major centres across the UK staffed by consultant allergists offering a full-time service with expertise in all types of allergic problems. A further nine centres staffed by allergists offer a part-time service, while the majority of clinics are run part-time by consultants in other disciplines. "As serious allergies affect more than one area of the body, you need a specialist clinic with dedicated staff who can look at the allergy as a whole rather than the patient being shunted between dermatology, chest and ENT departments, depending on which symptoms they have presented with at the time," says Professor Warner.

Research into the whys and wherefores of allergic reactions may yet lead to a vaccine to prevent or a drug to treat them. This may be of help to Sofia in the future. For now, says Dominic, "We're taking it one step at a time. She may grow out of it. Whatever, she will certainly be much better informed than I was."

"People's attitudes are probably the biggest challenge," Liz adds. "There's a tendency for people to see it as just another food fad, along with detoxing and the Atkins diet. But it's a real ailment like diabetes or asthma - yes, it's manageable, but you do need understanding."

Allergy UK helpline: 020-8303 8583; www.allergyfoundation.com

Anaphylaxis Campaign: 01252 542029; www.anaphylaxis.org.uk

HOW TO MANAGE A FOOD ALLERGY

* Get an accurate diagnosis, so that you know exactly to what you are allergic, eg, brazil nuts but not peanuts. "Finding out what you are allowed to eat is as important as what you are not, if you are to have any quality of life," says Professor Warner.

* Get accurate advice from a dietician as to how to tell which products do and don't include your particular allergens.

* Be vigilant. Don't be timid about asking people about the contents of food. Ask the waiter to check with the chef, for example.

* Ensure that you have rescue treatments with you at all times (and asthma medication, if necessary); that it's within its use-by date and that you know how to use it; and wear a MedicAlert bracelet.