Learning objectives

By the end of this chapter, participants will be able to:

• list the tests available to support allergy diagnosis
• know what guidelines recommend for allergy diagnosis
• recall the main concepts and applications of molecular allergology that can be used to support clinical diagnosis of allergy.

A brief introduction to allergy

• Allergy is an adverse immunological hypersensitivity to harmless foreign substances that can lead to several types of disease.¹
• These triggering foreign substances, mostly proteins, are called allergens and can be found in various tissues, particles, foods and organisms.²
• Manifestations of allergy range from relatively mild symptoms, including urticaria, wheezing and sneezing, to severe and life-threatening symptoms, including anaphylaxis.¹
• The European Academy of Allergy and Clinical Immunology (EAACI) has called for improvements in the prevention, diagnosis and treatment of allergy.³

Burden of disease³

Allergy is the most common chronic disease in Europe.
150 million EU citizens suffer from chronic allergic diseases and, by 2025, more than 50% of all Europeans will suffer from allergy.

• There is wide variation across Europe in terms of allergy services provided and access to specialised healthcare professionals.
• Around half of all identified allergy patients in Europe are managed in primary care, but there are recognised variations in the level of training received.
• Allergies should not be underestimated, especially where there is risk of anaphylaxis; they hold the potential to impact significantly on quality of life, education performance, career progression and personal development.
• Further, estimates for the avoidable indirect costs of failure to properly treat allergy in the EU are in the range of €55–151 billion every year.
• With proper treatment, which relies on an accurate diagnosis, an estimated €142 billion per year could be saved.

How does allergy develop?^4–6