harlequin nail

A fingernail of a heavy smoker who abruptly quit; the proximal zone of new growth is pink while the outgrowing nail formed during nicotine exposure—the ‘nicotine sign’—is a dirty yellow-brown without the pink
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

harlequin nail

A fingernail in a person who abruptly stopped smoking; the proximal zone of new growth is pink while the outgrowing nail formed during nicotine exposure–the 'nicotine sign' is a dirty yellow-brown
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
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