Conference chair, Professor Jonathan Brostoff opened proceedings by demonstrating that the first exposure to a substance (eg peanut) could have a different result depending on its route into the body. Through the mouth, the immune system is likely to develop tolerance. Through the skin, there is a likelihood that the immune system will develop sensitivity.
Anaphylaxis – recognition and management
Dr Andrew Bentley, consultant physician at Wythenshawe Hospital in Manchester, described how anaphylaxis is frequently misdiagnosed or missed through inexperience and lack of awareness. Doctors need to familiarise themselves with anaphylaxis.
If someone comes to you with suspected anaphylaxis, look for features and check for history of asthma but give adrenalin immediately. In a review of 56 deaths from anaphylaxis, a third had measurable evidence of asthma. Most deaths occur when no adrenalin is given within 30 minutes. Drug- and sting-induced anaphylaxis will provoke a faster reaction than food-induced anaphylaxis.
The EpiPen should be prescribed if the allergen is unavoidable or unknown; if there is a high risk of exposure; if the reaction is systemic; if there are classic symptoms and if there is a history of asthma.
Patients need clear information and reassurance that intramuscular adrenalin is safe in the appropriate dose. Instruction by an allergist can reduce fear around self-injection as well as complications arising from ineffective application.
Anaphylaxis: causes and presentations
Dr Harsha Kariyawasam, consultant in allergy at the Royal Free Hospital in London, listed potential allergens:
Milk: children show symptoms by 12 months – reassure parents that they will be able to tolerate in future. They will need regular reviews with an allergist.
Egg: children normally show symptoms within six months. Some children can tolerate cooked eggs. This allergy is also often outgrown.
Seafood: increasingly common in adulthood. People are often allergic to different species but until you find out, advise patients to avoid all species of fish and crustacean.
Fruit and vegetables: peanut is most life threatening. Among Israeli babies given peanut snacks, three in 4,000 are sensitive to peanut; in the UK, one in 70 is sensitive. The UK government advice to avoid peanut in pregnancy and infancy may be wrong…
Bee/wasp stings: treatment depends on species so identify the insect. Patients with severe reactions should be offered immunotherapy, and advised to take precautions.
Exercise-induced anaphylaxis: some co-factors are wheat, viral cold, painkillers, protein drink, heavy protein meal and alcohol. Not enough is known about this yet.
For idiopathic anaphylaxis (where there is no obvious or known allergen) doctors can send off serum for tests on the mast cells.
www.epipen.co.uk will alert you when your EpiPen goes out of date. Out-of-date adrenalin will still have more effect than none.
The ‘old friends’ hypothesis
Professor Graham Rook of University College, London asserted that allergy (and maybe many autoimmune conditions) are the result of a defect in the regulation of the immune system that affects those in developed rich countries who have dramatically reduced their exposure to micro-organisms (helminths, worms or parasites). Over millenia these microorganisms established a symbiotic relationship with our immune systems by which the latter was ‘regulated’ or kept in check.
For more on ‘old friends’ see John Scott on p6 and future
issues of Foods Matter.
Worms versus allergies
Professor David Pritchard from the University of Nottingham has been leading research into the safety and efficacy of infecting patients with respiratory conditions and Crohn’s disease with hookworms. The trials aim to assess whether the worms do indeed have an immunoregulatory effect on these conditions.
Although there is much more work to be done, results of both the Nottingham trials and those elsewhere have proved very encouraging.
Click here for more on helminthic therapy.
Moulds, pollen and thunderstorm asthma
Professor Jean Emberlin of the University of Worcester noted that there is a 3% increase in hospital admissions for asthma-related conditions after thunderstorms, but no-one is quite sure why. These admissions are usually atopic, often with a history of hay fever, likely to be allergic to grass pollen, and are outside when the storm starts.
Professor Emberlin’s research has found that starch granules released from pollen grains in wet weather become electrostatically charged by thunderstorms. These charged particles are able to get further down into the lungs. The larger deposits of these allergenic particles could be the trigger for asthma attacks.
The changing faces of allergy
Professor Martin Church from the University of Southampton related that 200 years ago, only 28 patients were known to suffer from hay fever, and they were all among the aristocracy. The physicians that first encountered allergy rightly guessed it would increase and cross class. Over the last 40 years there has been a massive increase in allergy. He suggested some factors that might be relevant in the allergy jigsaw puzzle
There is less allergy amongst farming people: being dirty can be good only if only you have the right genes and are exposed at the right time.
House dust mites thrive in the warm, damp conditions such as those found in double glazed and centrally heated houses. House dust mites die in cold and dry conditions.
There is a direct link between stress levels, the endocrine system and the immune system. Stress in pregnancy is transferred to the foetus. Children whose parents divorce before they are two have a three times higher incidence of allergy – significantly worse for children than passive smoking!
Diet and lifestyle
Obesity doubles the rate of atopy. We are not taking enough exercise or getting the right
Global warming means an increase in CO2. Plants love CO2, and the pollen season is becoming longer and more intense: birch is spreading north, and ragweed has arrived from the US. Both are major allergens. There is increased pollution in urban areas. Pollution affects dermal membranes that can then be penetrated by pollen.
Nutrition and allergy
Professor Philip Calder of the Institute of Human Nutrition, University of Southampton focused on the effects that antioxidants, fatty acids and probiotics can have on treating or modifying the risk of atopic dermatitis and asthma.
Antioxidant nutrients delay the damage that oxidative stress does to our cells, particularly in areas with a high oxygen content, such as the lung. Some
trials show that lung function improves with ingestion of the juice of fruits such as apples but provide minimal proof of improvement with a disease that has taken root.
Our dietary intake of omega 6 fatty acids (linked to a higher prevalence of atopic disease) has increased, but our intake of omega 3, which opposes the actions of omega 6, has not. Studies show that increased intake of omega 3 improves lung function and decreases asthma severity. Early exposure to omega 3, studied through fish oil ingestion in pregnant women, can be beneficial.
Gut bacteria differ between allergic and non-allergic children: the former have fewer than, and different species from, the latter. Probiotic gut bacteria can have an effect on allergic diseases but the type of bacteria is very important.
An Ecomed Viewpoint
David Freed and John Mansfield
Asthma incidence is on the rise and there are many reasons why. Nutrients essential to the immune system are in decline, levels of toxins, in the forms of pollutants, medicines, additives and certain foods, have risen. The lung is an excretion organ and some toxins only get excreted through the lung. Sneezes, coughs, inflammation and other bronchospasms happen for a reason, preventing bad things getting in, and helping bad things get out, of the body.
So is allergy good for you, in which case perhaps we shouldn’t be suppressing these symptoms with medication? Might it be better instead to desensitise allergic people and encourage optimal nutrition instead?
An ecological approach to asthma and anaphylaxis must look at prevention, avoidance and increasing the body’s resistance. Before the child is two, exposure to potential allergens can produce tolerance. Women should eat a broad diet in pregnancy, and foods should not be avoided unless the mother or infant reacts to them. Likewise the mother can give the baby foods from her own diet (liquidised or other) as the baby will be prepared for them. Caesarean sections delay the colonisation of useful microbes in infants; antibiotics should be avoided where possible.
In essence, Margaret advises assessing dietary deficiency and excess and prescribing a suitable diet with carefully balanced supplements.
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