It is an unusual event for a textbook covering such a national and international networks and the use of highly specialized field as contact dermatitis to be standardized methodology, a highly differentiated published in its fourth edition within a time period picture can now be painted; we know the major p- of 13 years. When the European and Environmental fessions at risk, as well as the influences of age and Contact Dermatitis Research Group was founded in various cofactors. This is a solid basis for preventive 1985,one of the major goals was to edit a textbook of measures. A new allergen, described in one center, high scientific standard written by renown experts can now be tested on a large scale in a short time and keep it regularly updated. The greatest danger period. If the data evaluation shows an unacceptably for a textbook is to become outdated – then it stays high rate of sensitization in the exposed population, on the bookshelf and is rarely consulted. The contin- regulatory measures will be undertaken to protect uous flow of new medicaments, the fascinating the consumer. A recent example is the “methyldib- improvements in diagnostic image analysis and ever- mo glutaronitrile story. ” changing operative procedures are the reasons for These and other issues of importance are covered considerable knowledge deficits in old textbooks, in depth in the newest edition of this textbook.