title: Naproxen-induced lichen planus: report of 55 cases.
abstract: BACKGROUND
  Clinical and histopathological differential diagnosis is usually impossible in drug-induced lichen planus (LP) and idiopathic LP. Naproxen is a nonsteroidal anti-inflammatory drug, which is widely used for its analgesic, antipyretic and anti-inflammatory effects. To the best of our knowledge, two case reports on naproxen-induced LP have been reported.
  
  
  METHODS
  Fifty-five patients with LP, and a history of naproxen intake before their eruption, were investigated.
  
  
  RESULTS
  Twenty-five patients (45.5%) had a history of naproxen intake prior to their eruption without any other medication. Twelve patients (21.8%) had a history of simultaneous use of naproxen with other drugs that were reported as inducers of LP. Eighteen patients (32.7%) had given a history of using naproxen together with drugs that had not been previously reported as inducers of LP. Moreover, in 42 patients, eruptive-type LP development after naproxen intake, is an interesting observation. New lesions were not observed after the cessation of naproxen intake in any of the patients.
  
  
  CONCLUSIONS
  Naproxen might be accepted as an important inducer for LP, especially for the eruptive form.
authors.affiliation: Department of Dermatology, Faculty of Medicine, University of Dokuz Eylül, Izmir, Turkey.
authors.forename: Ali Tahsin
authors.initials: AT
authors.lastname: Güneş
authors.forename: Emel
authors.initials: E
authors.lastname: Fetil
authors.forename: Turna
authors.initials: T
authors.lastname: Ilknur
authors.forename: Bahar
authors.initials: B
authors.lastname: Birgin
authors.forename: Sebnem
authors.initials: S
authors.lastname: Ozkan
mesh_terms: D000293:Adolescent; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008010:Lichen Planus / Q000139:chemically induced* / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009288:Naproxen / Q000009:adverse effects*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D009288:Naproxen