Allergic diseases are among the most common health issues children and adolescents face. Allergic reactions occur when the immune system becomes allergically sensitised and are detected by measuring levels of specific immunoglobulin E antibodies (IgE antibodies) in the blood. This article discusses the prevalences of bronchial asthma, hay fever, allergic dermatitis and allergic contact dermatitis for 0- to 17-year-olds, as well as the prevalence of allergic sensitisation to a mix of frequent inhalant allergens (SX1) among 3- to 17-year-olds based on data from the second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2, 2014-2017). 12-month prevalence trends between KiGGS Wave 2 and the KiGGS baseline study (2003-2006) are shown according to gender and age group. There were no significant changes in the 12-month prevalence of hay fever (8.8%) allergic dermatitis (7.0%) and bronchial asthma (3.5%) compared to the KiGGS baseline study, which indicates a stabilisation at a high level. More than one in six children (16.1%) currently suffer from at least one of these three diseases. 37.1% of 3- to 17-year-olds are sensitised against the multiple allergen mix SX1. Similar to the development of disease prevalence, SX1 sensitisation too has remained stable at a high level over the course of the past ten years.