Allergy – a widespread illness
Allergies are widespread. Virtually everyone knows somebody among their family members or acquaintances who is affected by a pet hair allergy, neurodermatitis, hay fever or asthma. Because allergies have been on the increase for many years now, virtually all around the world.
In Germany it is estimated that one in five adults is affected. According to information from the German Allergy and Asthma Association (DAAB), in Germany the allergy rate is particularly high in children. For example, around one in three children reacts to birch pollen or cat hair, with a runny nose, watering eyes or itchy skin. The problem is even more apparent in some other countries, such as in Australia and New Zealand, where almost half the population suffers from an allergy.
Additional information
Deutscher Allergie- und Asthmabund e. V. (DAAB)
An der Eickesmühle 15-19
D-41238 Mönchengladbach
Phone 0 21 66 - 64 78 820
Fax 0 21 66 - 64 78 880
www.daab.de
www.facebook.com/daab.allergie
Deutsche Atemwegsliga e. V.
Geschäftsstelle
Raiffeisenstr. 38
D-33175 Bad Lippspringe
Phone: 0 52 52 – 9 33 615
Fax: 0 52 52 – 9 33 616
www.atemwegsliga.de
www.facebook.com/atemwegsliga.de
Gesellschaft für Pädiatrische Allergologie und Umweltmedizin e. V.
Rathausstraße 10
D-52072 Aachen
Phone: 0241 - 980 04 86
Fax: 0241 - 980 02 59
http://www.gpau.de/
Also a question of hygiene in childhood
Whether an allergy develops in a child or even in an adult depends first and foremost on genes and specifically on whether there is an increased predisposition to a disease due to a person’s genetic make-up. If there is, although this cannot be predicted using tests, this does not mean that the affected person will actually have allergic reactions. There is however an increased risk that an allergy could develop as a reaction to certain environmental factors.
Allergies are not therefore directly inherited. However genes are passed on to offspring which can result in an increased predisposition to develop allergies. This explains why children with parents who have allergies are at greater risk of illness than children whose parents do not have allergies.
Over recent years it has been shown that the hygiene conditions in which a child grows up are some of the most important environmental factors in terms of allergies. Children who grow up in circumstances where there are few germs appear to be more susceptible to allergies. This could explain the observations that the allergy rate is much higher in children in industrial nations than in developing countries. Children with several siblings and those who grow up in a communal situation or on a farm also develop allergies less frequently than only-children and children who have a very sheltered upbringing.
Scientists have at least attempted to explain a seemingly unexpected link. The immune system appears to rely very much on being trained in childhood. It is evident that it must repeatedly deal with invading foreign substances such as bacteria and viruses, but also other irritants, in order to learn which irritants must be tolerated and which must be repelled. If this "training" does not occur, as is the case with children who grow up under very good hygienic conditions, the immune system is not properly matured. It then reacts to substances that would otherwise be tolerated, with an exaggerated reaction, in other words with an allergy.
Data from the German Federal Health Survey, 1998, also suggest that it is the condition in childhood that are more responsible for the emergence of allergies than environmental pollution.[1] This government-supported research tested, among other things, how the allergy rate differs in the West and East of Germany. It was discovered that the allergy rate in the West is considerably higher than in the East, with women more frequently affected than men in both parts of Germany. Generally 40 percent of those surveyed stated they had an allergy. Up to 47 percent of women were affected, and 33 percent of men. According to the health survey the frequency was very high among women living in the western states of Germany aged between 30 and 39, at 62 percent.
Although the frequency of allergies generally decreases with increasing age, in the study there was a surprisingly high rate (25 percent) in 70 to 79 year-olds. In this group there was also a marked difference between the West (27 percent) and the East (14 percent).
[1] German Federal Health Survey 1998; Das Gesundheitswesen. Special edition 2, Volume 61, December 1999; © Georg Thieme Verlag Stuttgart · New York
It starts with sensitization
The way in which an allergic reaction develops has been comparatively well researched scientifically. The reaction observed is always preceded by a period of sensitization, in which the body comes into direct contact with the allergen. Allergens can be breathed in or taken in with food or taken into the body via an insect sting, for example. During the sensitization period the immune system classes the invading substances as potentially dangerous and produces special antibodies against them.
If the immune system is confronted again by the allergen that it is now familiar with, these antibodies (immunoglobulins) attach onto the allergen and make contact with the immune cells, which it trys to eliminate. At the same time the messenger molecule histamine is released, which stimulates the allergic reaction and also elicits further reactions, such as rashes and itching, and also a runny nose and watering eyes.
Finding a needle in a haystack
If someone is suspected of having an allergy, it is necessary to find out specifically what substances the patient has an allergic reaction to. Looking for the relevant allergen is like looking for the proverbial needle in a haystack. However just like in criminology, medicine uses various indicators to significantly narrow down the range of possible triggers.
Often the patient’s past history, the anamnesis, provides indications of an allergy. The doctor wants to know when the symptoms occur, what happened before them and whether there is a noticeable link with certain situations (certain rooms, contact with animals, eating certain foods). Hay fever is a likely cause if there is a lot of sneezing, sniffing and watering eyes at a specific time of the year. By considering the time of year and the flowering period of trees, grasses and other plants that are known to trigger allergies, the allergens responsible can be narrowed down. Discussing the medical history also clarifies whether the family has any known allergies and especially whether the father or mother also suffers from an allergy. Admittedly an allergy is not inherited, but a predisposition to develop allergies is. If an allergen is known to trigger allergies in a parent or in siblings, this can possibly also provide clues about a patient’s situation.
A skin test is also often carried out for further diagnostic investigation, where common allergens are introduced into the surface of the skin (e.g. a so-called prick test). After around 15 to 20 minutes the doctor checks whether the introduced allergens have triggered a reaction in the skin, usually in the form of a rash (reddening, blistering). More laboratory tests after taking blood can then add to the diagnostic investigation. These can then be used to determine whether the body is producing increased amounts of the antibodies that are characteristic of allergy sufferers.
If in doubt it may also be necessary to carry out a provocation test. This involves confronting the affected patient with the allergy trigger under medical supervision, whereby he or she inhales it while in the surgery, for example. If the characteristic symptoms subsequently arise, the allergy and allergen are confirmed. If not, the search for the trigger continues.
Avoiding the trigger as much as possible
In the diagnostic investigation of the allergy, sometimes a great deal of effort is used to find the allergen that triggers it, so that the patient can subsequently avoid confrontation with this allergen as much as possible. In the professional jargon avoiding the allergen is also known as allergen abstinence.
With many allergy triggers, allergen abstinence is at least partly possible. A patient who has an allergic reaction to strawberries can cross this off his or her menu. It is more difficult with a pollen or dust mite allergy, although even with this type of disease there are possible ways of significantly limiting contact with the allergen. Hints and tips about the possible options there are can be found in the description of the different types of ailment, such as hay fever or a dust mite allergy.
Alleviating symptoms
There are not as yet any drugs that can be used to cure an allergy. But there are good options that can be used to alleviate or remedy the symptoms caused by the allergic reaction. Generally those affected are treated with drugs which block the effect of the messenger molecule histamine on the body's cells, for example. Because it is the histamine, among other things, that causes the allergic symptoms. If its effect is prevented, often the symptoms improve.
In severe cases treatment with cortisone can also be necessary. Cortisone is a naturally occurring hormone produced in the body in the adrenal cortex, which has anti-inflammatory properties and also lessens allergic reactions. Corticosteroids can be applied to the skin in the form of creams, inhaled as a spray or swallowed as a tablet, and of course even injected in the event of an emergency.
For a tolerant immune system
For many allergies the exaggerated reaction of the immune system can be lessened by means of allergen immunotherapy. The aim of this is to effectively retune the immune system and gradually accustom it to the allergen. The body is successively confronted with slowly increasing dosages of the respective allergen. This has to be done very carefully and the treatment must therefore only be carried out by an experienced doctor. There is a risk that there could be a severe allergic reaction if the therapy is not carried out in the correct way. Before starting the specific immunotherapy you have to understand that this treatment must be carried out consistently over the course of two to three years if it is to be successful. Allergen immunotherapy therefore requires a high level of compliance and commitment from patients.
However it does not have the same degree of success for all types of allergy. As a rule it works very well for people with pollen allergies. The prospects of success are somewhat lower for a dust mite allergy. In contrast the prospects of allergen immunotherapy for an insect sting allergy are especially good. After specific immunotherapy around 90% of patients react less severely to an insect sting after completing treatment.
Allergies are not all the same — different types of reaction
While the basic process is always the same with allergies, there are different types of allergy. They are differentiated as immediate hypersensitivity (type I hypersensitivity), cytotoxic hypersensitivity (type II hypersensitivity), what is known as an immune complex hypersensitivity (type III hypersensitivity) and delayed hypersensitivity (type IV hypersensitivity).
Immediate hypersensitivity
In type I hypersensitivity, which is the most widespread allergic reaction, the symptoms, such as breathing difficulties, a rash or itching, occur immediately after contact with the allergy.
Cytotoxic and immune complex hypersensitivity
In these two less common types of allergy (type II hypersensitivity and type III hypersensitivity) the symptoms occur a few hours after contact with the allergen.
Delayed hypersensitivity
This group includes allergic reactions where skin lesions, for example, may sometimes take 12 hours to appear after the allergen contacts the skin.
Allergic to pollen
Red, itchy eyes, sneezing fits, a runny or even a blocked nose and also tiredness, difficulties concentrating, possibly limb pain and a general feeling of exhaustion – these kinds of symptoms present themselves in people with hay fever as soon as pollen season begins. Often a bit of sneezing and sniffing are not the only symptoms. Many pollen allergy sufferers feel really unwell. They are plagued by unbearable itching around their eyes and sometimes even in their ears, they are no longer able to perform to their best and often have difficulties breathing. Around 15 % [1] of Germans have their spring ruined by these kinds of symptoms every year!
The symptoms, also known as "pollinosis", are triggered by the pollen from trees, bushes, grasses, crops or herbs. The pollen enters the nose, mouth and bronchial tubes in the air we breathe and when it comes into contact with the mucous membranes, after relevant sensitization it causes the immune system to react. Usually the symptoms occur within just 30 minutes after inhaling the pollen. You can assume you have hay fever if the sneezing happens quickly, quite suddenly, and lasts an unusually long time, i.e. several weeks. If the symptoms always occur at the same time of year, this is also an indication.
As well as the general symptoms, which can have a huge effect on the quality of life of those affected, there is also another reason that this type of allergy - doctors also call it seasonal allergic rhinitis - cannot be dismissed as a minor ailment. If the allergy is not recognized and treated in good time, it can spread and move from the upper to the lower respiratory system. Allergic asthma can develop as a consequence. The consequence of this is disastrous for the affected person. Because with an allergy of the lower respiratory tract patients no longer only have to contend with itchy eyes and a runny nose. They also cough and some have severe breathing difficulties as a consequence of allergic asthma. Without appropriate treatment this is a potentially life-threatening illness (see asthma guide). Around one third of patients [1] with hay fever experience this progression to the lower respiratory tract in the long term.
Treating hay fever
When treating seasonal allergic rhinitis, allergen abstinence – i.e. avoiding contact with pollen as much as possible – is paramount. However, this does not mean you cannot set foot outside throughout the flowering season, during the spring and summer, because hay fever generally only occurs while a certain tree or grass species is blooming. Therefore, those who suffer from pollinosis (hay fever) absolutely must get tested by an allergist in order to find out which specific allergen the immune system is rebelling against. If the symptoms primarily occur during the first few months of the year, it is often an allergy to what are known as "early flowering plants", such as hazel or elder. In the case of symptoms at the end of March or beginning of April, birch is suspected to be the allergy trigger. At the end of April many grass and cereal species start to bloom. Later in the year herbaceous plants such as plantain and mugwort flower.
It should be noted that cross-reactions can also occur with hay fever. Specifically, this means that those affected are not only hypersensitive to a particular type of pollen, but also to other allergens that are similar in structure. Examples of well-known cross-reactions include those between tree pollen and stone fruits, nuts, carrots and celery; between grass and cereal pollen and flour; and between weed pollen and spices, herbal teas, cosmetics, chamomile and celery.
Even with the best will in the world you cannot entirely escape the pollen flying through the air. The level of the pollen count depends upon the weather conditions, as on fine, sunny summer days the pollen can be carried through the air up to 500 kilometers. You can find out when, where and what pollen count to expect via the weather service’s pollen count calendar, daily newspapers, radio or television.
But even if you exercise some caution on days with a high pollen count, it does not help 100%. Other measures are necessary. These include a general antiallergenic treatment. Various groups of active agents are available, such as antihistamines. These are substances that block the effect of the messenger molecule histamine, which is released in the first phase of an allergic reaction. Antihistamines can be taken as tablets or as eye or nose drops. Modern active agents are well tolerated and, unlike medications in the past, barely cause any tiredness.
In addition to antihistamines, corticosteroids are used. These drugs are used topically (locally active) either as a spray for inhalation or in the form of an eye ointment, for example. This allows the side effects of the medication to be kept to a minimum in many cases.
The patient may also consider allergen immunotherapy after consultation with his physician, as this is particularly promising for hay fever.
Tips for allergen avoidance with hay fever
We have put together a few tips to help you suffer less from hay fever:
[1] German Federal Health Survey, Gesundheitswesen 61 (1999), special edition 2; Hermann-Kunz E., Robert Koch-Institute (Berlin), "Hay fever prevalence in Germany", P94-P99
Excessive reaction to hamsters
It is extremely painful for many pet owners when the doctor reveals that your symptoms are an allergic reaction to your beloved pet and diagnoses what is known as a pet hair allergy. Strictly speaking those affected do not react to the pet hair, but to allergens that stick to the pet hair, for example, the animal’s dander or saliva, which are released into the air from the hair and are then inhaled. Like other forms of allergy, pet hair allergies have also increased in recent years. Particularly common allergy triggers include cats, dogs, birds and most especially rodents, such as hamsters, guinea pigs, mice and rats.
If sensitization has occurred, the animal by no means has to live in the home for symptoms such as breathing difficulties and itching to occur. All it takes is a zoo visit, a stay on a farm or for especially sensitive people, even being near someone who owns a dog or cat.
Anyone suffering from an allergy where the trigger is unknown should therefore also consider the possibility of a pet hair allergy. In this case you should inform your doctor that you have a pet or have occasional contact with animals. Together with the doctor you can consider how allergen abstinence (allergen avoidance) can be achieved in each individual case and how the situation can be addressed generally using antiallergenic treatment.
Limiting the menu
Not every intolerance to certain foods is actually a food allergy. This term only refers to reactions that are actually caused by an excessive reaction of the immune system to certain allergens present in the food. The most common allergy-triggering foods are cow’s milk, chicken eggs, nuts, flour, shellfish and spices.
In addition, there are often cross-allergies. This means that those affected react to different triggers with a similar allergen structure. People with allergies to birch, elder and/or hazel pollen often also react to certain foods, specifically hazelnuts, celery or apples. The allergens concerned are very similar in structure and are wrongly classed as "potentially dangerous" by the immune system.
The top priority with food allergies when the allergy is known is to cut that particular food from the menu. However, in the case of an allergy to nuts, it is not sufficient to avoid eating nuts. In fact, when shopping, care must be taken not to put any products in the cart which contain nuts, or even traces of nuts, which is often not easy. In the case of allergies to milk protein or eggs it may be difficult to consistently avoid these products, as milk protein and eggs are hidden in many foods. It is helpful to examine the manufacturer's declarations carefully. An allergy diary can help with finding out which foods are tolerated and which are not.
Allergy to the tiniest arachnids
People with a dust allergy are not generally allergic to dust, but rather their immune system overreacts to allergens present in the excrement of dust mites. Dust mites are tiny arachnids which are found in their millions in house dust and their excretions have a very high allergenic potency. These microscopic creatures feed on flakes of skin. For this reason, particularly high numbers of mites are found near the bed and in carpets and upholstered furniture, in other words, wherever flakes of skin accumulate or wherever dust tends to gather.
This has nothing to do with poor hygiene, as the little arachnids are abundant in every home and in every bed. After all, humans lose around 1.5 grams of flakes of skin each day. That doesn’t sound like much, but it is enough to feed over one million mites.
Whenever dust is stirred up, for example when moving furniture or even when vacuuming, the allergens contained in the mite excrement disperse into the air and can be inhaled. Allergy sufferers react to the inhalation of these highly allergenic dust particles with itchy and watering eyes, sneezing, a runny nose and in severe cases even with breathing difficulties.
Unlike hay fever, the symptoms do not appear at a certain time of year, but are almost uniformly severe virtually all year round. For some dust mite allergy sufferers, symptoms are somewhat more pronounced in the fall months. This is because dust mites normally live for two to four months, especially during the summer time. As a result, the concentration of their excrement in dust increases significantly during this time, meaning dust allergy sufferers are more likely to have problems in the fall than in the spring.
Tips for allergen avoidance with a dust mite allergy
As with hay fever, there are also several ways to minimize contact with allergens in the case of a dust mite allergy:
Insect sting allergy
Allergies to bee and wasp stings are rare in comparison to other allergies. Nevertheless, they are especially feared as the reaction to insect stings is rapid and can be very serious for those affected. Reactions include itching, a rash, breathing difficulties, shivering, dizziness and nausea. In severe cases it can also lead to the collapse of the circulation, known as anaphylactic shock, which is potentially life threatening and requires emergency medical assistance.
Patients with a known severe insect sting allergy should therefore always carry an emergency passport with recommendations concerning the assistance measures to be taken immediately. Those affected are also usually given an emergency kit by their doctor, containing an antihistamine, a corticosteroid and an emergency medication (adrenaline), which can be quickly inhaled or injected if the worst comes to the worst. The antihistamine and the corticosteroid should be taken straight after an insect sting, whereas the adrenaline should only be used if the symptoms are indicative of anaphylactic shock.
Is also advisable to consider allergen immunotherapy, which is usually successful in reducing the hypersensitivity of the immune system to these allergens, especially for those with insect sting allergies.
Of course, people with insect sting allergies should take the necessary precautions to avoid being stung by bees or wasps. If possible they should not go near bee or wasp nests or walk barefoot outside on the lawn in summer and should be extremely careful when consuming sweet food or drinks, as they attract bees and wasps. For insect sting allergy sufferers it is also sensible to keep the bedroom window shut at night or attach an insect screen to the windows as a precaution.
Allergic to contact
Alongside the respiratory tract and the gastrointestinal tract, the skin in particular comes into contact with allergens. People who are allergic to certain substances develop what is known as contact eczema at the point of contact. It takes the form of a local immunological reaction to a specific allergen. The point of contact begins to itch, reddens and becomes flaky. In severe cases blisters develop. The skin cracks, weeps and later crusts form over the area of damaged skin.
Contact eczema is often triggered by nickel, chromium and other metals. Preservatives and other ingredients in cosmetics or dyes in textiles may also cause such reactions. This also applies to detergent, hair dye and perfumes and even plants such as primroses, garlic and ivy.
There are two strategies for contact eczema: Firstly it is necessary to determine what triggers the rash and to avoid it as far as possible. Secondly the changes in the skin must be treated in a targeted manner. In addition, you must pay attention to ensuring particularly good skin care and you should regularly use emollient and moisturizing ointments and creams.
Unbearable itching
Neurodermatitis is also a condition which is caused by an overreaction of the immune system. This skin reaction does not just occur on contact with a certain allergen, it is actually chronic, as people with neurodermatitis react to numerous substances in the environment with typical skin inflammation. Even heat and cold or physical irritation (for example from tight clothing) can cause excruciating skin reactions.
Along with bronchial asthma, neurodermatitis, also known as atopic eczema, endogenous (coming from within) eczema or atopic dermatitis, is one of the most common chronic illnesses among children – an increasing trend. The main symptoms are reddening and flaking skin, intense itching and in severe cases a serious inflammatory rash, sometimes with weeping skin. The changes appear predominantly on the inside of the elbows and back of the knees, but can also affect other parts of the body.
Treatment of neurodermatitis involves regularly balancing the dryness of the skin by using emollient skin care products. Ointments, creams and lotions are used. A distinction is made between measures to reduce inflammation, and in doing so to alleviate the allergic reaction, and those for basic skin care. Regular skin care is an absolute must for anyone suffering from neurodermatitis. It is essential that the skin is protected from further dehydration, which can often only be achieved by taking regular baths using oils and applying emollient and moisturizing creams. Using special emollient ointments, creams or lotions can also prevent redness and skin irritation and reduce itching.
In the case of targeted antiallergenic therapy, corticosteroids are applied to the skin. In severe cases the intended outcome of their application is that the symptoms subside and the itching – which automatically leads to scratching and therefore skin damage – is prevented, breaking the cycle of itching, scratching and bleeding skin. In order to minimize the side-effects of cortisone treatment, ointments and creams containing cortisone should be used exactly as the doctor instructs. Once the skin symptoms have subsided it is often sufficient to treat with emollients and creams, which must be continued rigorously in order to pre-empt a renewed outbreak of neurodermatitis.
