Each year, about midsummer, millions of children and adults begin to show various significant allergy symptoms. They sneeze, their eyes itch and become watery. They feel wretched for a month or two. Then the symptoms abate. These persons are suffering from attacks of hay fever - a prime example of what physician would call an allergic reaction.



To understand what allergies are, we must point out that when the normal equilibrium of the human body is threatened by an external agent, a sequence of automatic defense mechanisms moves into action. If the body becomes overheated, for example, it begins to perspire in order to cool itself. If it becomes too cold, it starts to shiver in an attempt to get warm.

An allergy is also a response to an external agent. But in this case the response to this outside source is severe and the reaction is neither normal nor desirable.

There are literally hundreds of possible causes of allergy, and the reaction may express itself in the human body in many different ways. One person breaks out in hives when he eats strawberries. Another starts to sneeze in the presence of dogs or cats. A third reacts to ordinary house dust. Some people have asthmatic attacks when faced by an emotional crisis.

The symptoms of allergy may first appear at any time from infancy to old age. They occur most often, however, before the age of twenty. Indeed, one of the major problems facing the doctor who treats allergies is to recognize the condition early enough so that he will be able to start treatment when it can do the most good.

Many allergic reactions are mistaken for other, less serious, conditions, especially in the case of infants and young children. Parents often neglect to mention these reactions to their physician until they have recurred several times.

It has long been known that inheritance plays a significant part in allergy. A person who has to allergic parents or whose family has a history of allergy has up to ten times as much chance of developing an allergy as a person from a non allergic family. Moreover, his or her symptoms will usually appear at an earlier age than would otherwise be the case.

However, persons with no trace of an allergic inheritance may also develop allergies, and some members of an allergic family may be completely free of allergic illnesses during their entire lives. There is not always a direct relationship between the type of allergy in the offspring. For instance, a mother with asthma may have one asthmatic child, another who suffers from allergic skin disease but who is free of asthma, and a third who shows no signs whatsoever of any allergy.

It is not allergy itself, but rather a tendency or susceptibility to allergy, that is passed on from parent to child. A person may have a tendency to manifest allergic reactions and yet never experience a single moment of allergic illness. His or her system is prepared at all times to react violently to an allergic assault. Fortunately, however, he or she will never have to come upon an allergic substance under conditions which would lead to a visible reaction.