title: Possible lansoprazole-induced eosinophilic syndrome.
abstract: OBJECTIVE
  To report a case of myalgia with eosinophilia related to lansoprazole administration.
  
  
  METHODS
  A 50-year-old white woman developed severe myalgia 1 week after starting lansoprazole. During the treatment course, the patient was also found to have eosinophilia. The myalgia and eosinophilia resolved 40 days after lansoprazole was stopped and 18 days after prednisone therapy was begun. The patient was not rechallenged with lansoprazole.
  
  
  CONCLUSIONS
  To our knowledge, this is the first reported case of lansoprazole-induced eosinophilic syndrome. Clinically, it is difficult to distinguish between eosinophilia-myalgia syndrome and eosinophilic fasciitis, which are probably part of a continuum of eosinophilic disorders. This patient presented with symptoms of both syndromes. Although other causes cannot be completely ruled out, the time course strongly suggests that lansoprazole was the causative agent.
  
  
  CONCLUSIONS
  It is important to consider medications when diagnosing patients with hypereosinophilia and/or myalgia.
authors.affiliation: Department of Pharmacy Practice, University of Florida, Gainesville, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Smith
authors.forename: K L
authors.initials: KL
authors.lastname: Chang
authors.forename: J G
authors.initials: JG
authors.lastname: Gums
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents / Q000009:adverse effects*; D016603:Eosinophilia-Myalgia Syndrome / Q000139:chemically induced* / Q000150:complications; D005260:Female; D006801:Humans; D064747:Lansoprazole; D008875:Middle Aged; D009853:Omeprazole / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D064747:Lansoprazole; D009853:Omeprazole