Anergic reactions and anergic diseases are found in many fields of medicine. As wen as affecting the skin, allergic diseases occur in internal organs such as the lungs and the kidneys and in the vascular and nervous systems. Interdisciplinary understanding and cooperation thus seem necessary to get a better insight into allergic reactions in the different fields of medicine in order that we may give our patients the best diagnostic and therapeutic care. Allergic diseases are on the increase. Studies from Sweden show that 15% of the population there are atopic, and some people speculate that in Germany about 10%-15% of all adults suffer from one of the many different allergic conditions. We in our clinic also have the impression that the incidence of atopic reactions has increased in recent years. The figure of 15% would mean something like 200 000 people in Munich alone! We all know that a wide variety of environmental factors can induce allergic reactions in the skin, the respiratory system, or internal organs. The most important anergens in our environment are pollen, molds, animal dander, housedust mite, food or food additives, various insects, industrial compounds and drugs. The direct costs of hospital and community medical care, other services, and drugs to help patients with asthma, hay fever, and skin allergies have in­ creased considerably in the last 10 years. The figures should make it clear to everybody that we are dealing with a health and environmental problem of great practical importance.