Allergic conditions are common and have been increasing worldwide.  Around 30-40% of the population have a predisposition to develop an allergy.

The term allergy comes from the Greek and means “reaction to what is foreign or different”.  Immunologically, an allergy is defined as a hypersensitive reaction by the body to certain – mostly naturally occurring – substances.  An allergy is thus not an immune deficiency but instead a misdirected overreaction by the immune system.

Allergy-like symptoms which are visible on the skin or mucous membranes can be evoked by intolerances of different kinds, or by pseudo-allergies, even in the absence of a prior immunological reaction to the substance itself.

 Symptoms

The interaction between allergens and specific antibodies triggers a reaction in the body. The resulting allergic inflammation can lead to quite differing symptoms: they could be a swelling of the skin, hives, eczema, itchy or teary eyes, sneezing attacks, a dripping or stuffy nose, coughing, shortness of breath, or even include abdominal pain, diarrhea or circulatory shock.

 Allergic conditions include: 

• hay fever (pollinosis) or a constant runny or stuffed nose (rhinitis)
• inflamed sinuses 
• bronchial asthma
• food or drug allergies and intolerance
• latex allergies
• insecticide / insect venom allergies
• atopic eczema (dermatitis/neurodermatitis)
• nettle rash (urticaria/hives) 
• swollen skin (angioedema or Quincke’s edema)

Evaluation and diagnosis

It is only with the help of a longer and detailed conversation that we can establish together what the possible trigger or cause of the symptoms or condition might be. This information is key in deciding which diagnostic tools might be relevant, and  these tools might involve  

• various skin tests
• laboratory and blood tests
• nasal, oral, conjunctival provocation tests
• measurement of nasal resistance (rhinomanometry)
• sense of smell tests 
• endoscopies
• lung function measurement (exhaled nitric oxide, spirometry)

Treatment

In addition to detailed consultation and explanations, treatment is provided which either addresses symptoms or probable causes. The goal is a treatment suited to an individual’s condition, one that is both effective and has few side effects.  The most promising allergy-specific treatment lies in strengthening immunological tolerance through hypo-sensitization (also called desensitization).  Depending upon what triggers the allergy, a targeted immunotherapy can be carried out, either classically using subcutaneous injections or administering substances under the tongue.  80-90% of all patients treated experience improvement in their symptoms and can even become entirely symptom-free. 

For certain patients, newer monoclonal antibody therapies may help.  This can be the case in moderate to severe cases of ‘TH2-mediated’ diseases such as atopic eczema, bronchial asthma, chronic rhinosinusitis with nasal polyps, or chronically recurrent  urticaria.  This treatment is both conservative yet promising.  It may be able to help control the course of the disease and restore the quality of life.  The goal is to make patients symptom-free while avoiding side effects or complications. 

Clinical immunology addresses diseases both cellular and humoral associated with the body’s defense system.  As such conditions can be both complex and chronic, their treatment often calls for interdisciplinary cooperation and consultation among various medical specialists.