Getting to know

In some cases, particularly when the allergen is suspected to cause allergic eczema or contact urticaria, the allergens are simply applied to the skin for a specific time without the skin being punctured. In these tests, allergen solutions or, for example, raw foods can be used. For the diagnosis of contact urticaria, the allergens are left on the skin for up to 30 minutes. If a swollen, red, itchy reaction occurs at the contact area, the test is considered positive and the allergen is recognised as the cause of the symptoms. If the allergen is suspected to cause atopic dermatitis, the allergens are left on the skin for up to 48 hours. The appearance of an eczema-like reaction (redness, swelling, blisters and eventually crusts) at the site where allergen was applied indicates a positive test and a very high probability of the allergen being the cause of the symptoms.