The incidence of allergies is increasing worldwide. Beside the well-established symptomatic treatments and subcutaneous immunotherapies, formerly known as de- or hyposensitization, a new form of treatment, local immunotherapy, has been developed in recent years. Local immunotherapy, though still controversially discussed, promises to be a curative, noninvasive, and easily applicable treatment for allergies. This volume summarizes the most current information on local immuntherapy compiled by internationally renowned specialists. In the methodology section, general aspects of local immunotherapy are presented including its history, allergen resorption and biodistribution, mechanisms of oral tolerance and practical experiences. The second section devoted to efficacy and safety presents findings from international placebo-controlled studies on nasal and sublingual immunotherapies with different allergens and for different allergic conditions including asthma and eczema. Possible side effects are also discussed. The concluding chapter critically evaluates the future prospects of this new method, pointing out still unresolved issues such as the exact immunological mechanisms, its long-term effects, or the standardization of dose and application intervals/duration. This state-of-the-art account will be of particular interest to scientists working in the field of allergy, clinical allergologists, pharmacists, and representatives from the pharmaceutical industry.