The uniqueness of this textbook lies in the fact that, it is the FIRST book in the field of allergy addressing in detail the various diagnostic and therapeutic procedures. The rationale behind presenting this book is to appraise the reader regarding the underlying principles of such procedures and to identify the limitations as well as usefulness in clinical practice. The chapters do include both traditional and modern methodologies representing the global nature of the specialty. Authors have been drawn across the globe to represent the variety of such procedures used in clinical medicine. This textbook will be appealing to medical students, physicians-in-training as well as consultants.