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Understanding Allergy / Intolerance

The immune system should respond to fight off invading bacteria, parasites, viruses and other threats to our well being. It should react differently (or not at all) to things such as house dust mites, pollens and foods, but in certain people the wrong type of ‘aggressive’ antibodies are produced in response to contact with these normally harmless substances. Once this has happened, further exposure to the same substance will lead to an immune reaction, causing symptoms in the affected person.

The substance itself does not cause the symptoms – it is the body’s unwanted reaction against the substance, which makes one ill. The immune system sets off a chain of events which is our defence mechanism – some symptoms may arise within minutes, and last for only a few hours; other symptoms may not begin for many hours after exposure to the offending substance, and these ‘delayed’ reactions can last for up to several days. Because they are so slow to arise, and so long lasting, it can be difficult to associate the symptoms with exposure to a particular substance. You may end up just feeling generally lousy all the time.

Many different symptoms can be produced by these immune responses. The immune system is present throughout the body, and when reacting to something it triggers the release of a host of natural chemicals that have a wide range of effects, even in areas such as the brain. These chemicals can sometimes be released even when no unwanted antibodies can be detected by blood or skin tests, so that a patient who is not regarded as truly ‘allergic’ gets the same sort of problems in contact with certain substances (intolerance or sensitivity reactions).

Most people think of allergic reactions causing conditions such as asthma, eczema, or dramatic swelling of the mouth and throat or other tissues (angioedema), or life threatening collapse (anaphylaxis). In fact migraine, gut symptoms (‘irritable bowel’), bloating (fluid retention), lethargy, depression, arthritis, muscle pains (myalgia), bladder problems, eye symptoms, mouth ulcers and a number of other symptoms can be caused by the immune system response (although they may, of course, have other causes). Even a patient with ‘straightforward’ asthma commonly feels lethargic, irritable and depressed for some time after an attack; the patient who has chronic, continual asthma or another allergy may feel like this virtually all the time due to the steady release of the immune system chemicals.

There are various treatments for allergic, intolerant and sensitive patients, which are beyond the scope of this document.

However the most important aspect in every case is avoidance of those substances which trigger a response. This can be achieved either by eliminating, or reducing the levels of, the trigger substance (allergen) in the environment, or by stopping the patient coming into contact with it.

There are some important points to remember;

  • The immune system tends to respond more to substances (allergens) that it comes into contact with repeatedly
  • It is the control of the immune system, which goes wrong allowing ‘mistakes’ to arise; therefore it is not unusual to develop several sensitivities together, or over time. Once the immune system over-reacts repeatedly the patient can get into a vicious circle; the more you react, the more likely it is that you will react to other things as well.
  • There are certain substances which commonly cause problems, and tend to be associated with certain symptoms, but everyone is different. What is a problem for one person may not be a problem for another. The symptoms an allergic person gets depends on where their immune system chemicals are released; what triggers the reactions will depend on what the immune system has been in contact with, and other factors.
  • Allergy is essentially an inherited condition, but not everyone develops their allergic symptoms straight away. Some babies are born already sensitive, or become so rapidly, but many people have no apparent allergic symptoms until they are ‘triggered’ by some sort of major stress in their life (virus infection, trauma, mental stress, and drugs). Some may never be triggered at all, so that the allergies apparently skip a generation

These points explain why allergen avoidance is important not only for those people who are already sensitive (to help with existing problems, and to prevent new ones developing), but also for anyone who may have a tendency for allergies, but has not yet developed them.

There are three main groups of substances which may trigger reactions – food, inhalants (or aeroallergens) and chemicals. Nutrition is also vitally important.

Foods

The treatment of complex food allergies should be done through a Doctor and does not concern us here.

There is however some basic important aspects:-

  • Avoid repetitive eating. Eat the widest variety of foods that you can, and don’t eat the same foods day after day. If you have toast every morning or egg salad every lunchtime, or peas with every evening meal, these will be repeatedly stimulating the immune system. Adopt a simple rotation; whatever you have eaten today, leave for a couple of days before eating it again. You will need to think about ingredients; it’s no good rotating breakfast cereals if they all contain wheat.  Libraries and health shops have books about rotating foods, with menu ideas etc.  Use fresh foods wherever possible. Avoid heavily processed foods, a high sugar intake, and large amounts of tea, coffee and fizzy drinks, but generally rather than cut large numbers of foods out of our diet it is better to include as many as possible, but don’t eat them too often. Research shows that wholefoods and organic foods usually contain far higher levels of vitamins and minerals than foods grown ‘normally’ or processed. 

You should not avoid specific foods without seeking advice. Restricting the diet by food avoidance can affect nutrition, but also tends to lead to the over-eating of the remaining foods in the diet, which can increase the risk of developing sensitivity to them.

Inhalants

This group includes pollens, moulds, animal dander and house dust mites.
House dust mites are probably the most important inhaled allergen; reducing exposure to them is the most fundamental aspect of allergen avoidance. They are found in large numbers in most houses in the UK; they require a food source (shed skin scales), warmth, and humidity to survive.
Skin scales are found in abundance in bedding, soft furnishings and carpets. Each night we warm up our beds as we sleep, shed skin and provide moisture through perspiration and breathing (roughly a pint per person per night); therefore high levels of mites are found in bedclothes, mattresses and pillows. Each mite passes very small faecal pellets (about 30 microns); these are extremely dry as the house dust mite needs to conserve as much moisture as possible. These pellets fragment easily into particles, which become airborne very easily, and remain airborne for many hours. They are of a size which our defences find most difficult to keep out of our airways, and they are therefore easily inhaled. As they land on the surface of the airways they set up an immune response; because they will act as a repeated stimulus to the immune system, in the susceptible patient allergy may well develop.

The house dust mite sensitive patient is normally worse at night or first thing in the morning, but mites are also present in carpets, soft furnishings, soft toys etc., and we will therefore be exposed to them to a certain extent all day. This and the fact that a reaction which is triggered in the night can last all day (or for several days) means that constant, chronic symptoms may develop.

There are several ways of approaching the control of house dust mite exposure:-

  • The most important area to tackle is the bed. Wash bedding regularly. Mites in bedclothes will be killed if you can hot wash them 60oC and above Although normal cool washing does not kill mites, it does wash out the allergic component of the pellets that causes the problem, and it will be some time before the levels rise again. Pillows are supposed to be washable but in practice it can be difficult getting them dry, and mattresses can’t be washed at all. Therefore pillows and mattresses hold high levels of mites and every night their pellets are breathed in as we sleep. They should be covered with a special breathable barrier cover, which is robust, and of proven effectiveness (especially around the closure). The duvet should also be covered in the same way unless it is washable and is regularly washed. Mattresses on slatted bases, which allow good air circulation, are an advantage if possible. Bedding carrying the Allergy UK Seal of Approval can be safely trusted as it will have been tested to ensure that house dust mite allergen cannot escape through the covering or in some products house dust mites are unable to live within the bedding.
  • Kill them with, high temperature steam cleaning of carpets, mattresses etc (high-temp steam leaves things dry rather than wet); or by freezing (e.g. pillows, soft toys).
  • Remove them from mattresses and soft furnishings by using an Allergy UK endorsed anti allergy and anti bacterial bed vac.
  • Increase ventilation to lower humidity. One of the reasons for the increase in house dust mite problems in recent decades is poor ventilation leading to higher humidity, which tends to encourage mite growth. Reducing humidity levels can reduce mite levels, and as it also controls mould growth and reduces indoor air pollution (often worse than outdoor pollution) improved ventilation/lower humidity is important. This can be achieved by opening windows, air vents, and opening doors while the house is occupied, although this may be unrealistic due to outdoor pollution or pollens, noise, heating costs and security.
  • The best alternative option is a good air filter and a dehumidifier especially if the house is particularly damp. There are many air filters on the market that will trap larger particles such as whole pollen grains and mite pellets, but fragmented pellets and pollens, and some mould spores, are of a size (up to one micron) which most easily get through our defences. Up to 95% of the airborne particles in a room will be of this size, and they are also the most difficult particles for an air filter to remove it is therefore important to use one that has been tested as beneficial and awarded the Allergy UK Seal of Approval.
  • Filter vacuum cleaners – the small size of the most troublesome particles means that they pass straight through the coarse filter and dust bag of a normal cleaner and are blown around the room (thus many dust allergic people are worse after vacuuming). Simple measures include getting someone else to vacuum, opening windows wide during vacuuming, and not doing it so often – damp dust instead (but not with a cloth that is too wet, or humidity will rise) A built-in vacuum system could also be considered.  Ideally an old vacuum cleaner should be replaced with one that is designed to effectively trap even the sub-micron particles which cause the problems. Allergy UK has worked extremely hard to improve the effectiveness of vacuum cleaners in reducing and removing allergens. By setting very high standards for manufacturersseeking the Seal of Approval they have been able to ensure that any vacuum cleaner bearing the Seal of Approval Award can confidently be used by allergy sufferers. Some people make one room (usually the bedroom) into an ‘oasis’ by removing carpets and unnecessary furnishings and clutter, reducing sites for mites to thrive and making the room easy to keep clean.

Pollens and Moulds

Grass pollen is commonly considered; tree and weed pollens are often ignored but as each has its own season ranging from January (Hazel) to October (Dandelion). If possible do not go out when the counts are high (hot, windy days); wear sunglasses to avoid pollens getting in the eyes; air filters are effective indoors (pollens are relatively large particles, although fragments are obviously much smaller); keep windows closed; change clothing and wash hair when coming indoors. Filter vacuum cleaners will trap pollens.

Mould spores are usually ignored but are potent allergens – very few allergic patients are not mould sensitive. Different moulds spore at different seasons, so mould sensitivity (as with pollens) can lead to year long symptoms, usually worse in spring and particularly autumn, in damp weather, when raining or snowing, and in gardens, around compost heaps, and when cutting grass. Measures to reduce humidity, increase ventilation, and good air filters will help tackle mould sensitivity, as may avoiding ‘mouldy’ foods such as blue cheeses, mushrooms and yeasts.

If you have a damp house, particularly where mould is visible on walls and windowsills, it is important to determine the cause and tackle it (either structural faults, or condensation due to inadequate heating or poor ventilation).

Animals

The allergic effects of dogs and cats is due to their dander (material from the fur, skin and saliva). Birds’ feathers can cause problems directly, or due to mites living in the feathers. No allergic person should allow their pets access to the whole house, and especially not the bedroom. Restrict them to one area and keep it clean. Filter vacuum cleaners and good air filters will help keep the load down, as will regular washing of dogs (and some cats will also tolerate being washed). High temperature steam cleaning is effective in removing the ‘reservoir’ of allergen in the carpets.

Chemicals

There are huge ranges of chemicals in everyday use (in excess of 50,000); more than 4 million different chemicals are registered for various uses in America. Some of these are known to cause allergy-type problems directly (this may be more widespread than many people believe); others in some way irritate people already allergic to other substances. Any chemical that we inhale or ingest has to be eliminated from the body through our detoxification pathways; these may fail to function adequately in people with immune system problems. Even low levels of chemicals, which would not normally affect a normal person, affect many allergic people. Reducing the load of chemicals to which we are exposed each day is therefore an important aspect to consider.

  • DON’T SMOKE or allow smoking in the house; if someone in your house just won’t give up, ask them to only smoke in one room and get a good air filter in there.
  • Don’t use perfume or hairspray.
  • Switch to unperfumed deodorants; use sticks/roll-ons, not sprays.
  • Use fragrance free shampoo and conditioner.
  • Use a ‘cleaner’ toothpaste, i.e. homeopathic, herbal, baking soda.
  • Don’t use air fresheners especially if you suffer from any airway irritation. If you feel that you really must have some form of air freshener use one that is endorsed to show that allergens within the product have been significantly reduced.
  • Use oxygen bleaches, not chlorine bleach. Borax can be put down toilet bowls, and for soaking clothes.
  • Cut down on the use of strong smelling disinfectants. Most people use disinfectants when they only need to clean with soap and water. When a disinfectant is needed use a non-taint, safer type.
  • Switch to an unperfumed soap powder of the ‘sensitive skin’ type (Boots, Surcare, and Ecover).
  • Cut down on the use of furniture polishes and spray cleaners; use pump sprays or tins rather than aerosols.
  • Half-used tins of paint, brush cleaner etc. should not be kept under the sink. Eventually the paint dries out in the tin – where does the solvent go? Into the air in your house!
  • When decorating use low-odour, solvent-free paints, varnishes and glues, and always ventilate well.
  • If buying new carpets and furnishings, sniff them well in the shop. There can be a big difference in makes. European furniture and materials often have to meet more stringent standards and give off less gases such as formaldehyde. Try to avoid cheap ‘chipboard’ materials; MDF is better, solid wood is best. Allow anything new to air off for a while before bringing it into use; if possible, ventilate rooms well until the smell goes.
  • Investigate an air filter for your car.
  • Avoid additives in foods as far as possible.
  • Consider fitting a water filter, or using a jug filter, but change the cartridge regularly, follow the instructions closely, and keep filtered water in the fridge.

There is much more information about a range of allergic symptoms, intolerances and allergen avoidance in a series of factsheets available from Allergy UK (www.allergyuk.org or 01322 619898).

Details of a range of products endorsed by Allergy UK to meet appropriate standards for allergy sufferers are also available from Allergy UK via the helpline or website.