Allergy: symptoms, causes and therapy

The range of possible allergies is vast – pollen, grass, animal hair, food, cosmetics or medicines. When the immune system attacks these harmless environmental substances, all sorts of complaints can occur: your eyes burn, your nose runs, and you cough, to allergic Asthma. Which symptoms are typical for which allergy, how does an allergy test work and what can be done to treat the allergy?

the course of an allergic reaction

If the immune system overreacts to contact with ordinarily harmless substances by regarding them as enemies and then produces antibodies, an allergic reaction occurs the next time you come into contact with this substance. Antibodies such as immunoglobulin E ensure the body’s defence cells release aggressive inflammatory substances. Histamine and other messenger substances lead to swelling, itching and dilated blood vessels. Depending on whether the nose, skin, bronchi or circulatory system are affected, this reaction can be localized or affect the whole body.

In addition to the reaction via antibodies, which often occurs minutes after contact with the “hostile” substance (the allergen), the immune system also has the option of allowing specific cells (T cells) to react to substances – this is how contact allergies occur. Here, the reaction often only happens after hours or days.

 

Allergy: symptoms and signs

An allergy can be accompanied by various symptoms, from cough, runny nose, or rash to gastrointestinal complaints – all of these can fall under the category of allergy symptoms. In the following, the typical symptoms of the most common forms of allergy will be discussed.

Symptoms of hay fever (pollen allergies)

The most common form of allergy is hay fever, which is caused by pollen. Hay fever typically affects the eyes and upper respiratory tract. In addition, allergic symptoms can occur on the skin if there is contact with an allergy-causing pollen.

Typical symptoms of pollen allergy include:

• red eyes with swelling, itching and dilated blood vessels
• allergic conjunctivitis
• Sniffles
• swollen nasal mucosa with obstructed nasal breathing
• Cough
• allergies Asthma
• Rashes, swelling or itching

Suppose severe allergies lead to allergic Asthma; thick mucus forms in the tense, swollen bronchi, making coughing difficult. In addition, there is the typical humming, rattling asthma breathing noise.

Another typical symptom of hay fever is the development of so-called cross allergies. Many plant-based foods, in particular, are similar in their chemical structure to specific pollen, so the body also perceives them as allergens. Cross allergies form, for example, to stone fruit or nuts.

 

Symptoms of house dust mite, animal dander and mould allergies

In addition to pollen allergies, the symptoms of which increase or decrease seasonally, some allergies exist all year round, mainly manifesting as problems in the area of ​​the eyes and upper respiratory tract. These include house dust mites, animal dander and mould allergies. If one reacts to the faeces of the tiny insects in the case of house dust mite allergy, the so-called animal hair allergy is proteins in the saliva of the animals that are distributed with hair and scales in the apartment. In the case of mould, the spores trigger allergic reactions.

Typical symptoms are:

• year-round allergic rhinitis
• itchy, red eyes
• conjunctivitis
• Cough
• sometimes, rash and itchy skin

In the case of a mould allergy, after eating food containing mould, abdominal pain, diarrhoea, and nausea can occur in addition to the symptoms mentioned above.

Contact allergy symptoms

As the name suggests, contact allergies occur after contact with the allergenic substance. These are often metals like nickel, but other triggers, such as certain ingredients in detergents or cosmetics, latex or medication, can also cause contact allergies. An allergic reaction to the adhesive can also occur with temporary adhesive tattoos. Allergies to henna tattoos are relatively rare.

As a rule, the following symptoms occur with a contact allergy:

• flushed skin
• sometimes, vesicles, pustules or nodules
• itching
• dry skin
• if symptoms persist, the thickening of the skin

Food allergy symptoms

The symptoms of food allergies vary greatly and can affect the upper respiratory tract, the gastrointestinal tract and the skin. More common food allergies are, for example, an allergy to chicken protein or peanuts.

Possible symptoms of a food allergy are:

• nausea and vomiting
• diarrhoea and indigestion
• inflamed conjunctiva and mucous membranes
• Sniffles
• Cough
• Shortness of breath due to narrowing of the bronchi or larynx
• redness and itching
• wheels
• swelling of the face
• Itchy mouth and burning tongue

 

Other forms of allergies

In addition to the forms of allergy mentioned above, there are other allergies and intolerances. The range is vast, so medical advice should always be sought if an allergy is suspected.

For example, piercings, tattoos or permanent make-up are not recommended for everyone – they can lead to an allergy if not appropriately handled. Another type of allergy is sun allergy. In the case of sun allergies, the skin reacts to UV-A radiation with small pimples.

Circulatory severe problems due to allergies

In some instances, the widening of the blood vessels can lead to severe circulatory problems – if the blood “slumps” in a reaction taking place throughout the body, cardiovascular failure occurs.

This life-threatening situation is called anaphylactic shock. It often occurs with insect venom allergies or after intravenous administration of certain drugs. As a rule, the symptoms become noticeable just a few minutes after contact with the trigger; in rare cases, they can also appear hours later. In the event of an anaphylactic shock, the emergency services should be alerted immediately.

Causes of an allergy

Why the immune system suddenly reacts allergically is still unknown. Allergies are increasing worldwide – there is speculation as to whether, in addition to hereditary influences, increasing environmental pollution or insufficient contact with germs in childhood are responsible. Over 20,000 allergy-causing substances are known: You can inhale them, take them with food or as medication and come into contact with them through your skin – even involuntarily, such as with a wasp sting.

The pseudoallergy, which shows similar symptoms to an allergy, is distinguished from the allergic reaction but occurs as soon as you come into contact with a substance – without the body forming antibodies. People often react pseudoallergically to salicylates (also to ASA ).

 

Diagnosis using an allergy test

If the above symptoms are present, it makes sense to seek medical advice and, if necessary, have an allergy test carried out.

First, the doctor will ask you about your symptoms to narrow their causes further – nevertheless, allergy diagnostics often remains detective work. A stuffy nose every morning can indicate a house dust allergy, but pets, pollen or mould spores can also be held responsible for many an allergy.

A wide variety of substances are then tested through a skin test. This is the so-called prick test. Different allergy-triggering substances are introduced into the top layers of the skin with the help of a lancet. A solution containing histamine triggers a reaction, and a saline solution, to which no allergic reaction should occur, is also tested for comparison. Redness, itching, and swelling indicate that the immune system responds to the substance. After 15 to 20 minutes, the result is checked by a doctor. Unfortunately, the skin prick test is not always reliable.

A blood test is another test method. The concentration of immunoglobulin E in the blood indicates whether an allergy is present at all. Results are reported in International Units per millilitre. A maximum of 100 UI/ml is average for adults and children over ten. The so-called CAP-FEIA or the ELISA test are common today; the RIST or RAST test, in which radioactive substances detect immunoglobulin E, needs to be updated.

In a provocation test, the person concerned is deliberately confronted with the possibly allergenic substance – for example, on the nasal mucosa or the conjunctiva. However, because of the risk of a severe reaction (anaphylactic shock), this is only rarely carried out and under medical supervision.

What helps against the allergy?

Tablets, nasal spray or eye drops for allergies – various drugs are used to protect the mucous membranes of the nose and bronchi from allergens. Most fall under the antihistamine drug group. So, they inhibit the effects of histamine in the body. Nasal sprays or eye drops have a local impact, while the active ingredients in allergy tablets also get into the blood. For this reason, some antihistamines can tire you since histamine has an activating effect on the body and, above all, on the nerve cells in the brain. Second-generation antihistamines have less impact on nerve cells, making them significantly less sleepy. Zinc can also help with hay fever. 

In addition to the nasal douche, cortisone is often used to combat swelling of the mucous membranes and inflammation. Still, the treatment for Asthma, in particular, has many different facets, including exercise.  

The allergy vaccination (hyposensitization) is lengthy but significantly reduces symptoms in the majority of those affected. This effect usually lasts for up to ten years. After that, repeating the therapy can be considered. In hyposensitization, the smallest doses of the allergenic substance are administered in tablet form or injected to make the immune system more tolerant of this substance.

Of course, each allergy has a particular procedure, including allergen avoidance, tips, and medication. You will find more detailed information under the respective disease.

Alleviate Allergy Symptoms: What Else Can You Do?

If you suffer from an allergy, it is best to avoid the responsible allergen, which is often easier said than done. In the case of a house dust allergy, there are many ways to keep the number of mites as small as possible. These include care tips, special vacuum cleaners or bed covers.

During the pollen season, you should stay indoors often and keep your nasal mucous membranes moist, for example, with a seawater spray. A nasal douche can also be helpful. Fortunately, ingredients in food now have to be identified more precisely so that an adapted diet is possible in the case of neurodermatitis, lactose intolerance or specific food allergies.

 

Preventing allergies in children

Allergies are hereditary, so predisposition plays a specific role in the development of allergies. However, there are a few tips that can help to counteract the development of allergies in children. When the child absorbs breastfeeding, small amounts of foreign proteins are present. As a result, the child’s immune system slowly learns to tolerate them. A healthy diet and exercise also help to stabilize the immune system and make it less sensitive to possible allergy triggers.