Supporting accurate allergy diagnosis: A practical leaflet for Healthcare Professionals

A newly developed Allergy UK leaflet focuses exclusively on validated diagnostic tests – those with the strongest supporting scientific evidence. These tests are recommended by the British Society for Allergy and Clinical Immunology (BSACI) and the National Institute for Health and Care Excellence (NICE). Healthcare professionals are encouraged to guide patients away from unproven or unvalidated methods, such as hair analysis or electrodermal (Vega) testing, which lack evidence and are not recommended for clinical use.  

Allergic disease encompasses a wide range of clinical presentations, including allergic rhinitis (hay fever), allergic asthma, drug allergies, atopic dermatitis, food allergies and venom allergies (including insect bites). Accurate diagnosis is essential to ensure appropriate management and treatment and to avoid unnecessary interventions or dietary restrictions. 

To support clinicians in identifying potential allergens responsible for patients’ symptoms, a range of diagnostic tests are available. These tests are designed to aid clinical assessment and should be used to complement – not replace – a thorough allergy-focused clinical evaluation. 

Allergy remains a clinical diagnosis. Diagnostic testing plays a supportive role by helping to confirm or exclude the presence of allergen-specific IgE antibodies (sIgE). This can be achieved through either skin prick testing (SPT) or serum-specific IgE blood testing, challenge testing (supervised feeds) and component resolved diagnostics a more advanced method of diagnostic testing which drills down to highlight specific individual proteins within an allergen.  

A detailed, allergy-focused clinical history is central to appropriate diagnosis and test selection. Key elements include the nature of symptoms, timing of onset and identification of suspected triggers. Supporting evidence such as photographs, for example, of rashes, urticaria, or angioedema, can also be valuable in guiding assessment. 

Diagnostic Tests Used in Allergy for Healthcare Professionals