Comprehensive ManualS' in Pediatrics are designed to broaden the practitioner's clinical scope by providing a wide range of diagnostic and management skills ordi narily considered to be the exclusive domain of the specialists. Although the series as a whole constitutes a comprehensive text in pediatrics, each volume stands on its own as a self-contained reference for the busy practitioner. In order to maintain a uniform style and coverage of each subject, each manual is usually written by no more than one or two authors. Each author is an acknowl edged expert in his or her field and provides a comprehensive, up-to-date account of the topic under discussion. Practically oriented, each volume offers concise guidelines and courses of treatment. Michael Katz E. Richard Stiehm Foreword Subspecialization in internal medicine and pediatrics is a relatively recent phe nomenon. When Dr. Jerry C. Jacobs began to develop his special interest in rheu matic disease approximately 25 years ago, there was a handful of pediatricians working in the field, and rheumatology was only slightly less strange than phre nology as a term for a discipline of modern medicine. For better or worse, rheu matology is an established subspecialty. Textbooks have been designed for the internist/rheumatol