One hundred years of allergen immunotherapy European Academy of Allergy and Clinical Immunology celebration: review of unanswered questions

Allergen immunotherapy was introduced by Leonard Noon 100 years ago and is the only disease-modifying treatment for allergic individuals. Improved under- standing of immunology has taught us a great deal about the underlying mecha- nisms involved in allergen immunotherapy; however, despite these developments, a number of important questions remain unanswered. Several of these questions relate to the practice of allergen immunotherapy in the clinic, such as: Is it possi- ble to unify units of allergen potency? Which treatment schedules are best? Is allergen immunotherapy effective in all patient groups? Is there a dose-response relationship for efficacy and safety?, and Is there evidence for long-term effects following allergen immunotherapy? Others are related to new developments, such as new indications, or developments in the production of allergens. On the cente- nary of Noon's discovery, European experts in the field of immunotherapy met in Geneva under the aegis of the EAACI to discuss these controversial issues. This study presents outcomes and conclusions from these discussions.