When people are confronted with the expression “allergy” they are often confused as to what it actually means. Allergy is a blanket term that includes a large variety of diseases with largely differing manifestation and, of course, requiring different therapeutic measures. Depending on what type of allergy a person suffers from, the attending physician will discuss the appropriate measures with the patient and implement them accordingly.  

Plainly said, allergy means that our immune system i. e. our defensive system goes haywire.  It is generally understood that our immune system has the function to protect our body from foreign and possibly pathogenic substances. An allergy is a disorder of our immune system which causes defensive overreactions occurring to normally harmless environmental substances. Such normally harmless substances may include e.g. food or food products (e.g. nuts, lacto proteins), metals (e.g. chromium, nickel), mould fungi, sunlight, house dust or grass pollen. Every substance triggering an allergic reaction in a person is referred to as ‘allergen’.   

The reasons for occurrence of an allergy are varied and have not yet been clearly defined. However, it has been found that several factors, such as hereditary loading, environmental conditions, pollination, climatic conditions or the psychological condition of the person affected may play a role and that a combination of such factors is present when an allergy is triggered.       

During the past years the number of patients suffering from allergic reactions has constantly increased. The occurrence of allergies predominantly takes place during childhood and youth or early adulthood and today every third baby already suffers from an allergic disorder. In Germany it is as many as eight to twelve million people per year who suffer from hay fever alone.  

Depending on the type of allergen a number of different symptoms may occur on their own or as a combination of several symptoms. Symptoms include, among others, respiratory diseases (e.g. allergic rhinitis, bronchial asthma), redness of the eyes, fatigue and tiredness, concentration disturbances, skin reactions (e.g. neurodermatitis), fever or inflammation of the conjunctiva.  

There is a large range of methods of diagnosing an allergy. In addition to a detailed interview by the attending physician, a cutaneous test is carried out as a standard. This is a so-named provocation test for which known allergens are applied to the skin in a concentrated form. If an allergy to one or more of these allergens is prevalent in the patient, an inflammatory reaction will occur at the point of contact (e.g. redness or urtication). According to the intensity of the skin reaction the degree of the allergic reaction can be defined. In addition, the presence of the immunoglobulin E as a marker in the blood identifies the presence of an allergy. However, it is only the presence of an allergy that is detected by means of this test; nothing can be learnt about the trigger or cause of the disorder.  There is a large range of other tests available that the attending physician will arrange for, if required.   

In Germany, approximately 8 to 12 million people are affected by allergic rhinitis. A rough differentiation is made between two types of allergic rhinitis; seasonal rhinitis caused by pollen, grass or trees (hay fever), on the one hand, and allergic rhinitis that is caused by other substances (e.g. animal dander) and that may occur all year round, on the other hand. Hay fever should in any case be taken seriously as, if not treated, the allergy may extend to the lower respiratory tract and cause asthma.
The most frequent symptoms are sneezing attacks, itching of the nose and the eyes, nasal dripping and nasal congestion and significant impairment of the general condition of a patient up to fever.  

Allergic skin disease is a blanket term for a number of different disease patterns for which the allergic reaction manifests in the skin. These include neurodermatitis, contact allergy and nutritional allergy. Neurodermatitis mostly begins during babyhood or infancy and approx. 5 in 100 children suffer from this disease. The symptoms characterising this disease are redness, puritus and scaling skin rash with the entire body or only the bends of the arms or the hollows of the knees may be affected.
Contact allergy is a local irritation of the skin including redness, puritus, inflammation or formation of vesicles. It is triggered through direct contact of the allergen, e.g. cleaning agent with the affected region.
Nutritional allergy will occur through consumption or mere contact with a specific food product or substance, e.g. strawberries. The reactions of the skin mostly occur on the hands or in the neck and facial region.  

A sudden and massive allergic reaction may lead to a severe state of shock in individual cases.  In addition to local symptoms, an allergy may also cause a so-named “anaphylactic shock” which is accompanied by sudden drop in blood pressure, increased heart rate, breathlessness and formation of wheals as well as severe puritus on the entire body. An anaphylactic shock represents a life-threatening condition and requires immediate medical treatment.  

For allergies there is no causal therapy, i.e. no possibility of fighting the causes or sources of the disorder; but the goal of treatment is exclusively relief of the symptoms. For this purpose, a number of drugs with largely differing mechanism of action are available today. In a therapy with cortisone or an antihistaminic agent the symptoms of the allergy are suppressed such that they only occur in attenuated form or not at all. To achieve this effect, however, regular administration of the drugs (available as spray, gutta/drops, tablets, etc.) is required. Antihistamine preparations block the most important inflammation substance in the body, histamine, which is released during an allergic reaction.
Cortisone suppresses the allergic reaction by reducing the disposition of the body for an allergic reaction.  

Unfortunately, in the most cases it is not possible to cure a once developed overreaction of the immune system. A method for attenuating the allergic reaction is the so-named “hyposensitisation”. In this therapy the allergen is injected subcutaneously in increasing dosages in order to prevent future overreactions to the allergen. For this procedure a large amount of time and patience is required and it is only reasonable if the symptoms can unambiguously be assigned to a specific allergen. However, this method has not proved successful in all patients.  

Only if it is clear and defined to what substance a patient has developed an allergy, there is a possibility of taking action. Naturally, the best therapy for an allergy is prophylaxis, i.e. the best way of preventing symptoms is preventing exposure to the allergen substance. If possible, patients should completely avoid contact with the allergen. Of course, in the case of house dust allergy or grass pollen allergy this is nearly impossible, yet in the case of nutritional allergies or an allergy to animal dander this recommendation may easily be followed. The attending physician will recommend appropriate measures, depending on individual cases and symptoms.