It is a great pleasure for me to see this work in print. As outlined by Dr. Traupe, at least 20 different types of ichthyosis have been identified to date. This book will effectively help to establish a correct diagnosis, as a basis for genetic counseling. Dr. Traupe proposes a new classification of the ichthyoses, based on reason­ able clinical criteria. He lets the reader share in his enormous knowledge and safely guides him through the difficult field of nomenclature. He describes the particular nature of these scaling disorders in a manner as simple as possible. During the last few years, research on ichthyosis has become a fascinating scientific challenge due to the introduction of novel investigative approaches. The main advantage of this book lies in the fact that the author successfully combines recent achievements made in lipid analysis, enzymology, electron microscopy, and molecular genetics. Heiko Traupe began his career in dermatology 11 years ago, as a resident in the Department of Dermatology in Munster. As we were both interested in the genetic aspects of skin diseases, this was the starting point of a most fruitful collaboration, which is still continuing. During our common work in Munster, Dr. Traupe was able, thanks to his unceasing clinical curiosity, to describe many novel aspects within the field of ichthyosis, and I took pride in coauthoring papers on new items such as cryptorchidism as a fea­ ture associated with X-linked recessive ichthyosis, autosomal dominant lamellar ichthyosis, and alopecia ichthyotica.