Many people use the term allergy to describe any reaction by the body which involves the immune system. Food intolerance, for example, is often mistaken for an allergy. I know at least one man who swells in the face after eating chicken. This is food intolerance or rejection -- not allergy.
A also know a woman who sneezes for a number of days after taking foods such as bread, buns, chapattis and others which are normally prepared from wheat flour. She faces the same predicament after drinking beer whose ingredients include wheat. This too is intolerance. Children (or adults) who experience food intolerance may feel sick or even vomit. In most cases, food intolerance is temporary.
However, the difference between intolerance and allergy is difficult to define unless allergens are determined. So, the enigma can only be unraveled after a medical diagnosis. The human body can exhibit a variety of other intolerances or rejections. Some women (or children), for example, develop swellings or even blisters after wearing metal earrings, bracelets, necklaces or bangles.
Clearly, this is a rejection or intolerance -- not an allergy. Now, let us take a closer look at allergies. I must point out at the outset that allergies develop because of a mixture of inherited and environmental factors. However, there is still a lot to learn about the causes of allergies. But it is already clear that some children inherit a tendency to allergies. These children’s bodies are easily triggered into inappropriately making the allergy antibody (called IgE) when they come into contact with common substances such as floor dust or the pollen of certain flowers.
Some cosmetic soaps, perfumes, oils and face powders have also been blamed for provoking allergies in certain people. Eating of certain types of nuts, especially groundnuts, has often triggered allergies in a large number of people. These children are said to be atopic. The way in which a child is first exposed to an allergen will determine whether or not they will become allergic.
The younger the child is and the larger the amount of allergen he or she is exposed to the greater the risk of becoming allergic to it. Adjuvant factors can increase the risk (such as pollution and cigarette smoke). Other factors, or co-factors, make the allergy more severe (for example, fever, exercise, cold air and certain foods). Some factors such as frequent colds or exposure to dirt in early life may protect against allergy. All children may develop allergies but atopic children
are at greater risk.
Symptoms depend on the nature of the allergic disease. In hay fever, for example, there is a stuffy nose and itchy runny eyes, while in anaphylaxis there is dramatic swelling of the airway, wheezing and collapse. Other allergic conditions include asthma, eczema and medicine allergies. Allergies can be diagnosed. The aim of diagnosis is to identify the cause (allergen). The most common diagnosis is skin prick testing, which is quick, simple and cheap, and can test for several allergens at once.
But it is less reliable in very young people, elderly people and for conditions such as eczema. Skin patch testing is useful in dermatitis, while blood tests are a good but more expensive way to spot allergies. Challenge tests, or provocation tests, may be useful to rule out an allergy. Some diagnostic tests, including hair analysis and Vega testing are not accepted as of any benefit by most of the medical profession.
Most allergies cannot by cured but in many cases the symptoms can be suppressed using medicines. Traditional suppressants in the form of herbs are also available. Allergen immunotherapy (desensitization) may effectively cure an allergy, but it is a long process. The medical world hopes there may soon be a vaccine to prevent allergies. Most conventional medical workers are not trained in tackling allergy, but there are specialist allergy medics.
Asthma is one of the most common allergies in children. It is a disorder of the respiratory system that can confound the parents of an ailing child. In asthma the mucosa, or lining, of the breathing tubes in the lungs (known as the bronchi) becomes chronically inflamed. Cells and chemicals from the immune system enter the lung tissues and the breathing tubes become hyper-reactive.
This means the tubes are easily triggered into constricting or narrowing, making it harder to move air through the lungs, and breathing becomes difficult. In addition, the mucosa or lining becomes swollen. Excessive production of mucus occurs. These changes add to the difficulty breathing. The exact cause of asthma is not clear but a combination of genetic predisposition and environmental influences can lead to increased reactivity of the airways.
These influences include atopy, an inherited tendency to allergic diseases such as eczema, hay fever and other types of allergy reactions, which affect a large number of children with asthma. Once the airways are hyper-reactive, a variety of triggers cause the sensitized lungs to react. This reaction leads to an asthma attack. The triggers of asthma include respiratory tract infections, allergens (particles such as dust, cow dung or pollen), smoking, cold air, emotional upsets and chemical irritants.
If one parent has asthma, the chance of one of a couple’s children developing it is about double that of children whose parents do not have it. Typical symptoms of asthma include a recurrent cough, wheeze and breathlessness, which are often worsened by trigger factors. Diagnosis is made on the basis of symptoms along with investigations such as a chest x-ray and lung function tests. In children aged above five years, the most useful test is one that measures the peak expiratory flow rate; a measure of how fast air can be pushed out of the lungs.
Unfortunately the diagnosis can be more difficult in smaller children, where other conditions often cause wheezing. Treatment includes medication given straight to the lungs through inhalers and relievers to open constricted airways. Steroids and other drugs prevent an imminent attack.