Book Review

Itch: Mechanisms and Management of Pruritus

N Engl J Med 1994; 331:281-282July 28, 1994

Article

Itch: Mechanisms and Management of Pruritus
Edited by Jeffrey D. Bernhard. 454 pp., illustrated. New York, Mcgraw-Hill, 1994. $50. ISBN: 0-07-004935-1

Did you know most itches target a small area that gets bigger as you scratch? Did you know there are different kinds of itch, just as there are different kinds of pain? Did you know that morphine inhibits pain and promotes itch, whereas naloxone and other morphine antagonists relieve itch? Did you know that pain will kill itch? How does scratching relieve itch, and why does it sometimes paradoxically beget more itching? Why does scratching lead a sleeping person to a stage of lighter sleep? The answers are in Itch: Mechanisms and Management of Pruritus.

A chapter called “Pruritic Curiosities” names some curious conditions. “Thinker's itch” is an itch “that makes people scratch their heads when thinking or perplexed.” The “red traffic light phenomenon” is observed when drivers stopped at a red light scratch their heads. “Telepathic pruritus” is a “delusion that someone is making you itch by mental telepathy.” “Pruritus prohibitus” is “the itch that you can't scratch because your hands are full, because you are standing in front of an audience, or because you have scrubbed for surgery.” “Piano player's practice pruritus” is “familiar to any parent who has ever convinced a child to practice the piano before the child was good and ready to do so.”

Before I read it, I had a prejudice against this book. Too many skin diseases, I believe, are treated on the basis of symptoms and signs rather than accurate diagnosis. To ask, “What's a good treatment for itch?” is analogous to asking, “What's a good treatment for chest pain?” Dr. Bernhard addresses the issue by including chapters on dermatologic conditions that cause itch but spends extra time on conditions that cause intense itch (e.g., notalgia paresthetica) and those that cause itch without any sign of skin disease at all (e.g., the itch of renal failure or pregnancy).

Itch is multiauthored, but the eight chapters written by Dr. Bernhard himself are among the most interesting. They are spiced with quotations, neologisms, and observations that make one by turns perplexed, thoughtful, and openly amused. Two chapters discuss the pathophysiologic aspects of itch, 12 chapters discuss pruritus associated with skin diseases, 10 discuss pruritus associated with systemic diseases, 1 discusses psychiatric aspects, and 4 discuss treatment. I liked Caroline Koblenzer's contribution in the chapter entitled “Psychologic and Psychiatric Aspects of Itching,” especially for its discussion of psychiatric drugs used to treat itching.

The book is the best on its subject. It suffers from its diversity; itch accompanies too many disorders. However, most dermatologists, and their patients with them, should gain a better understanding of a variety of pruritic disorders. Different audiences will pick out different chapters, because the book is “for anyone who sees patients with itch.” This book does more than simply scratch the surface.

Mark V. Dahl, M.D.
University of Minnesota Medical School, Minneapolis, MN 55455