This clinical trial is focused on studying a condition known as birch pollen-induced allergic rhinoconjunctivitis, which is an allergic reaction that affects the nose and eyes, often causing symptoms like sneezing, itching, and watery eyes. The study is also considering participants who have this condition along with asthma. The treatment being tested is called STALORAL® Birch 300 IR, which is an oromucosal solution, meaning it is a liquid that is applied inside the mouth. This treatment contains an extract from birch pollen, which is intended to help the body build a tolerance to the allergen and reduce symptoms over time.

The purpose of the study is to evaluate the safety and effectiveness of STALORAL® Birch 300 IR in children and adolescents aged 5 to 17 years. Participants in the study will be randomly assigned to receive either the STALORAL® Birch 300 IR treatment or a placebo, which is a substance with no active medication. Neither the participants nor the doctors will know which treatment is being given to ensure unbiased results. The study will last for a period of up to 13 months, during which participants will regularly use the treatment and report their symptoms and any changes they experience.

Throughout the study, participants will be monitored to assess how well the treatment works in reducing symptoms of allergic rhinoconjunctivitis and the need for additional medication. The trial aims to provide valuable information on whether STALORAL® Birch 300 IR can be a safe and effective option for managing symptoms in young people with birch pollen allergies, potentially improving their quality of life during the pollen season.