title: Impact of the positive pathergy test on the performance of classification/diagnosis criteria for Behcet's disease.
abstract: BACKGROUND
  The only diagnostic test that currently exists for Behcet's disease (BD) is the pathergy test. A positive pathergy test (PPT) is an important component of many of the 16 sets of classification/diagnosis criteria used to diagnose BD. The aim of this study was to determine the importance of a PTT in the performance of the diagnosis/classification criteria for BD.
  
  
  METHODS
  All patients listed in the BD registry of the Rheumatology Research Center, Tehran (6,727) and 4,648 BD controls were enrolled in the study. The diagnosis was clinical when no other diagnosis could explain the patient's manifestations. The criteria were tested with and without PPT results. Sensitivity, specificity, and accuracy were calculated.
  
  
  RESULTS
  Without PPT, all sets of criteria lost sensitivity, gained specificity, and lost accuracy, with the exception of the Cheng-Zhang criteria. The largest loss in sensitivity was for the Hubault-Hamza (35 %) and Dilsen (17.3 %) criteria; the least was for the Curth (1.9 %) and ICBD (6.5 %) criteria. The largest gain on specificity was for the Dilsen (4.7 %) and Curth (3.1 %) criteria; the least was for the Japan (0.1 %) and Japan revised (0.1 %) criteria. The greatest loss in accuracy was for the Hubault-Hamza (20.4 %) and Dilsen revised (9.3 %) criteria; the least was for the ICBD (3.6 %), while Curth gained 0.3 %.
  
  
  CONCLUSIONS
  Without PPT as a criterion for the diagnosis of BD, the sensitivity and accuracy of the sets of classification/diagnosis criteria decrease, while the specificity improves.
authors.affiliation: Behcet's Disease Unit, Rheumatology Research Center, Shariati Hospital, Tehran University of Medical Sciences, Jalal Al Ahmad/Kargar Avenue, 14117, Tehran, Iran. fddh@davatchi.net
authors.forename: Fereydoun
authors.initials: F
authors.lastname: Davatchi
authors.forename: Bahar
authors.initials: B
authors.lastname: Sadeghi Abdollahi
authors.forename: Cheyda
authors.initials: C
authors.lastname: Chams-Davatchi
authors.forename: Farhad
authors.initials: F
authors.lastname: Shahram
authors.forename: Zahra
authors.initials: Z
authors.lastname: Ghodsi
authors.forename: Abdolhadi
authors.initials: A
authors.lastname: Nadji
authors.forename: Massoomeh
authors.initials: M
authors.lastname: Akhlaghi
authors.forename: Tahereh
authors.initials: T
authors.lastname: Faezi
authors.forename: Hormoz
authors.initials: H
authors.lastname: Shams
authors.forename: Roghieh
authors.initials: R
authors.lastname: Larimi
authors.forename: Farima
authors.initials: F
authors.lastname: Ashofteh
mesh_terms: D001528:Behcet Syndrome / Q000145:classification / Q000175:diagnosis* / Q000276:immunology; D003951:Diagnostic Errors / Q000517:prevention & control*; D018450:Disease Progression; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000209:etiology* / Q000276:immunology; D011237:Predictive Value of Tests; D012042:Registries; D015203:Reproducibility of Results; D012867:Skin / Q000473:pathology* / Q000503:physiopathology; D012882:Skin Tests / Q000379:methods*