The primary intent of this book is to familiarize the medical
practitioner with the "nail unit" in a way which will render, correctly
and more easily, the diagnosis of nail diseases. At the same time, it
serves to encourage the treatment and corrective measures of the ab-
normalities, if possible, based on anatomical and physiological
knowledge. The chapters on anatomy, regeneration, and nail formation are
basic to the author's in- tent. The content ofthe references quoted
represents information which is proven and not controversial material.
In addition, my own material not previously published is included. I
would like to introduce the anatomical concept that the nail unit
consists of four dif- ferent epithelial structures, each with its own
characteristics, yet all interrelated. These four constituents are the
Proximal Nail Fold (PNF), the Matrix (M), the Nail Bed (NB) and the
Hyponychium (HYP). A disease may occur in any number of or all nail unit
structures. A clear understanding of the anatomy, histology, and tissue
kinetics of each constituent will be necessary and is the key factor in
interpreting the abnormal findings of each of these constituents as
disease occurs. It follows, therefore, that treatment and Cor- rective
measures should include the knowledge of not only the nail but also of
its relation- ship to the bony phalanx and the digit.
