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Woman with AllergyAllergy and intolerance: An overview of triggers, diagnosis and treatment

Allergies are commonplace nowadays. There is hardly anyone without an allergy or intolerance. Environmental conditions have changed and the burden on the body has become more diverse. No wonder we react to it very differently than our ancestors.

The skin, as the largest organ, offers the greatest point of attack, from both the inside and outside. This article deals with allergies and intolerances in general and what has to be considered in this regard relevant to ​​the skin. 

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Photo: © inesbazdar –

The following areas will be covered in this article:

What is the difference between allergy and intolerance?

These terms are often mentioned in the same breath but there are significant differences, especially with regard to the medical aspects:

  • An allergy is an overreaction of the immune system and is accompanied by the formation of antibodies.
  • Intolerances however, are disturbances in the metabolic process. The body cannot process certain substances. The best-known example is lactose intolerance. The body cannot break down lactose into its components because the enzyme lactase is missing.

Why do allergies and intolerances occur?

Humans and their immune systems do not always react the same way. What is harmless for most people can cause fierce reactions in a small amount of people. Allergens, as causes of allergies, can lead to different reactions in the immune system. Very often the skin is affected.

As a classic example, a nickel allergy is usually mentioned. It leads to redness and blistering of the skin even if superficial contact with nickel-containing metal (ring, bracelet, or jewellery in general) takes place.

Intolerances can also trigger symptoms on the skin. The most well-known situations where the body cannot process certain substances are lactose and gluten intolerances. They can lead to rashes, redness and the formation of wheals (itchy rashes on the skin).

If you notice any changes on your skin this should be medically clarified to rule out more serious diseases. You are welcome to arrange a consultation in our practice in Vienna.

How do allergic reactions on the skin come about?

We distinguish different types of allergies based on their triggers. In the case of a contact allergy, the causative agent comes in direct contact with the skin which then reacts. We all know the other types of allergies that are caused by food, liquids or taking medicine.

If, after contact with certain cosmetic products or cleaning agents, certain materials or textiles, you notice changes on your skin (rashes or itchy, weeping spots), this may be an indication of an allergy.

Most of these changes occur where the skin has come into contact with the causative agent (the allergen). If you suddenly get a rash on the back of your hand after putting on the new bangle it could be an indication that your body will not tolerate certain materials. The immune system is activated and starts to defend itself to a perceived harmful foreign element.

Similar symptoms can occur if something is eaten or drunk. Even if certain substances are in the air, allergic reactions (hay fever) can be the result if they get into contact with our mucosa. In contrast to incompatibilities, they usually start immediately and can have a severe effect. Book an appointment.

What allergic symptoms are possible? Can it be alleviated?

When the skin is just slightly irritated it is often sufficient to stabilize the skin surface with good care, moisture and special creams.

Heavy cases can, apart from the skin, also affect the mucous membranes, lungs and even the entire body. Patients with hay fever often suffer from watery eyes and sneezing during the pollen season. The most severe manifestation of an allergy is anaphylactic shock which can even lead to death.

Therefore, when severe reactions (pustules, wheals, breathing problems, swelling of the mucous membranes) occur, urgently consult a doctor. By means of an allergy test the dermatologist can identify the allergen causing the problems.

If you are suffering from allergic reactions you are welcome to do an allergy test at our practice in Vienna. You are welcome to make an appointment via our website.

Anaphylactic shock - the extreme reaction of the body

Anaphylactic shock is a pathological acute reaction of the body. Within a second the immune system is maximally activated and initiates a maximum response. The affected person and possibly those present are usually overwhelmed because the attack is so extreme and suddenly.

Anaphylaxis can present several phases and in extreme cases the final phase can be death. The triggers can be varied (bee stings, cat hair, peanuts, seafood, medicines) and death is based on the repeated intake of alien proteins.

In lighter phases and general reactions redness, rashes, hives on the skin, in combination with headache and internal restlessness can be observed.

At the first sign of anaphylactic shock it is advisable to secure all food and drink so that you can later identify what triggered the reaction. Many patients are not aware of their allergies and it is always a good idea to establish your allergy status.

How can intolerances affect the skin?

There is a possibility that patients are unable to distinguish between allergies and intolerances (incompatibilities). The difference is that intolerances do not lead to an immune response and no antibodies are involved.

In addition to the usual symptoms of the gastrointestinal tract, intolerance can trigger rashes, redness and hives. Most widespread incompatibilities are:

  • Histamine intolerance: Histamine is not broken down. It comes with the consumption of histamine-containing food leading to reactions that are not unlike an allergy such as rash and severe itching. Foods and stimulants with high histamine content are:
    • Sparkling wine, red wine, beer
    • cheese, salami, raw sausage
    • nuts
    • sauerkraut, eggplant, tomatoes, spinach, avocado
    • strawberries, kiwi, citrus fruit
    • yeast dough products
    • canned fish
    • chocolate
  • Lactose intolerance: the enzyme lactase is missing. Lactose is not split
  • Fructose intolerance: the body can only absorb fructose conditionally
  • Gluten intolerance: a protein from cereals attacks the intestinal mucosa

Atopic dermatitis associated with allergies and intolerances

If you suffer from atopic dermatitis, different combinations of food can have different effects patients. With a blood test, you can determine a variety of allergies and thus adjust your eating behaviour.

Atopic dermatitis sufferers also more commonly have hay fever and allergic asthma. It is important to identify the allergen in order to avoid the trigger or even to initiate immunotherapy.

For almost every food, there is an equivalent that is better tolerated and tastes just as good.


What makes our offer in allergology interesting for you?

imageAll of our dermatologists have further training in the field of allergology and in-depth knowledge of the treatment of allergies, intolerance and the associated secondary diseases. In our team, 4 dermatologists have completed the additional subject allergology. We offer various test procedures for your special requirements without long waiting times.


Dr Bounas-Pyrros is also senior physician at the Wiener Neustadt State Hospital with a special focus on allergology.



We use the most modern technology to identify your allergies. The Allergy Explorer (ALEX²) can identify allergen-specific IgE antibodies against all relevant allergen sources (exception: drugs, e.g. antibiotics). Whether it is animal fur, yeast and mold, insecticides, latex, mites, food or pollen - ALEX² helps to find the allergy trigger. ALEX² test is also loaded with many molecular allergens. These enable a better understanding of your allergy in the case of cross-reactions and food that is prone to risk for allergic reactions (e.g. peanuts) - this helps the doctor to suggest tailored diet recommendations (e.g. raw apples are not tolerated, whereas applepie do not cause any harm). With the help of molecular allergy diagnostics, allergen-specific immunotherapy (AIT) can also be used in a more targeted manner. ALEX² is equipped with almost 300 allergens.


As a patient, you benefit from this comprehensive test through a faster, safer and more comprehensive selection of therapies.


Some food allergens are more dangerous than others. Many are not tolerated in their raw state (e.g. apple) but Allergens can be destroyed by heat treatment (boiling / baking / frying / ...). However, there are also allergens that are not neutralized by heat treatment and can cause severe reactions.


Often the allergic career begins with a reaction to a single allergen source. Over time, other allergies to related allergy triggers can develop (e.g. birch pollen-apple syndrome). With an analysis at the molecular level, the primary allergen trigger can be identified, and the therapy designed accordingly.


 In contrast to other treatment options, AIT can treat the cause of the allergy by inducing tolerance to the relevant allergen source. AIT is available for insecticides, mites, pollen, mold and animal hair.

How does it work?

A blood sample is required for this test. The blood is then precisely analyzed for almost 300 allergens. After about 2 weeks there will be a clarification discussion with one of our doctors in which measures will be derived.

Please do not hesitate to contact us.


You are welcome to make an appointment for an allergy test in our practice in Vienna. Book an appointment




Photo prick test: © Microgen –


Photo patch test: © Katarzyna Leszczynsk –









You are welcome to make an appointment for an allergy test in our practice in Vienna. Book an appointment.



Allergy Explorer (ALEX2)

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  • Thank you Dr Bisschoff. The medicine you prescribed worked like a bom! I appreciate the time you took to descibe my illness in simple terms and the lifestyle changes I need to make to manage my condition. Many thanks! 
    Yelp: Christiaan B.
  • I traveled from London to see Dr. Johannes Bisschof for wrinkle treatment. I was extremely impressed with my wrinkle treatments. He has a very 'natural look' approach and after everyone asked me why I look younger and more relaxed I will definitely have it done again. I have also asked him advice on my skin texture and he suggested 2 creams and my skin has never looked this good. I feel 10 years younger. I can highly recommend him! 
    Yelp: Liezel M.
  • Dr Bisschoff used a laser to treat my skin scars. I was happy with the package that he offered. He is knowledgeable, friendly and I loved the end result.
    Google: Cecile du Toit
  • Dr. Bisschoff was absolutely wonderful and a great help. He took time to make sure I was comfortable, spoke incredible English, and explained everything in a careful and detailed manner. Thanks to his help, my skin condition was solved! I would recommend him to anyone.
  • Best dermatologist in Vienna. Really cares about his patient. He is a very good listener. He spent as much time as its needed and he doesn't rush patient. His aim is actually to help people not only earn money (like some of doctors tend to do). On the top of all of that he is really positive person and he explains everything in the proper manner.



  • Excellent doctor, extremely attentive! One of the best medical experiences I had.
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Allergy and intolerance - cause and therapy Average rating: 4.14 - of 29 visitors

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