"New Trends in Allergy IV" is a specialized book that addresses the increasing prevalence of allergic diseases in industrialized countries. The causes of this rise are not yet fully understood, with environmental factors, genetic predispositions, and socioeconomic aspects being discussed as possible influences. The book is based on contributions from an international symposium held in Hamburg in 1995, which brought together scientists from various disciplines. It provides a comprehensive overview of advancements in experimental immunology and allergology, highlighting both fundamental scientific findings and practical clinical diagnoses and therapies. The collected works in this volume reflect the current state of knowledge and the challenges that still need to be addressed in order to develop new therapeutic approaches.