3. Cracking the Case

  1. James C. Pile4,
  2. Thomas E. Baudendistel5 and
  3. Brian J. Harte6
  1. Jennei Wei1,
  2. Patrick P. Kneeland2 and
  3. Gurpreet Dhaliwal1,3

Published Online: 21 MAR 2013

DOI: 10.1002/9781118483206.ch3

Clinical Care Conundrums: Challenging Diagnoses in Hospital Medicine

Clinical Care Conundrums: Challenging Diagnoses in Hospital Medicine

How to Cite

Wei, J., Kneeland, P. P. and Dhaliwal, G. (2013) Cracking the Case, in Clinical Care Conundrums: Challenging Diagnoses in Hospital Medicine (eds J. C. Pile, T. E. Baudendistel and B. J. Harte), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118483206.ch3

Editor Information

  1. 4

    Departments of Hospital Medicine and Infectious Diseases, Cleveland Clinic, Cleveland, Ohio, USA

  2. 5

    Department of Medicine, Kaiser Permanente Medical Center, Oakland, California, USA

  3. 6

    South Pointe Hospital, Cleveland Clinic Health System, Warrensville Heights, Ohio, USA

Author Information

  1. 1

    Department of Medicine, University of California, San Francisco, California, USA

  2. 2

    Division of Hospital Medicine, Providence Regional Medical Center, Everett, Washington, USA

  3. 3

    Medical Service, San Francisco VA Medical Center, San Francisco, California, USA

Publication History

  1. Published Online: 21 MAR 2013
  2. Published Print: 15 MAR 2013

Book Series:

  1. Hospital Medicine: Current Concepts

Book Series Editors:

  1. Scott A. Flanders and
  2. Sanjay Saint

ISBN Information

Print ISBN: 9780470905654

Online ISBN: 9781118483206



  • antineutrophil cytoplasmic antibodies (ANCA);
  • cocaine;
  • hypothesis testing;
  • levamisole;
  • neutropenia;
  • purpuric skin lesions;
  • toxicity


Levamisole was initially developed as an antihelminthic agent. Its incidentally discovered immunomodulatory effects led to trials for the treatment of chronic infections, inflammatory bowel disease, rheumatic diseases and nephrotic syndrome in children. Levamisole was withdrawn from the market in 2000 in the United States due to its side effects. It was first detected in cocaine in 2002. In patients presenting with neutropenia and purpuric skin lesions - particularly with a predilection for the ears - levamisole-adulterated cocaine exposure should be considered. Although the discussant was familiar with this toxidrome from local and published cases, he was only able to settle on levamisole toxicity after a series of competing hypotheses were ruled out on the basis of irreconcilable features and by using analogical reasoning of neutropenia and antineutrophil cytoplasmic antibodies (ANCA) induction. The chapter explains this laborious process of hypothesis testing, which ultimately allowed him to crack the case.