title: Schnitzler syndrome: validation and applicability of diagnostic criteria in real-life patients.
abstract: BACKGROUND
  Schnitzler syndrome is characterized by an urticarial rash, a monoclonal gammopathy, and clinical, histological, and biological signs of neutrophil-mediated inflammation. The aim of this study was to assess the applicability and validity of the existing diagnostic criteria in real-life patients.
  
  
  METHODS
  This multicentric study was conducted between 2009 and 2014 in 14 hospitals in which patients with Schnitzler syndrome or controls with related disorders were followed up. We compared the sensitivities and specificities and calculated the positive and negative predictive values of the Lipsker and of the Strasbourg criteria for the patients with Schnitzler syndrome and for the controls. We included 42 patients with Schnitzler syndrome, 12 with adult-onset Still's disease, 7 with cryopyrin-associated periodic disease, 9 with Waldenström disease, and 10 with chronic spontaneous urticaria.
  
  
  RESULTS
  All patients with Schnitzler syndrome met the Lipsker criteria. According to the Strasbourg criteria, 34 patients had definite Schnitzler syndrome, five had probable Schnitzler syndrome, and three did not meet the criteria. One control met the Lipsker criteria and had probable Schnitzler syndrome according to the Strasbourg criteria. Sensitivity and specificity of the Lipsker criteria were 100% and 97%, respectively. For the Strasbourg criteria, sensitivity for definite and probable diagnosis was 81% and 93%, respectively, with a corresponding specificity of 100% and 97%.
  
  
  CONCLUSIONS
  Diagnostic criteria currently in use to diagnose Schnitzler syndrome are reliable. More investigations must be done to attest their efficiency in patients with recent-onset manifestations.
authors: Clinique Dermatologique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
authors: L
authors: L
authors: Gusdorf
authors: Unité d'Immuno-Hématologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors: B
authors: B
authors: Asli
authors: Service de Dermatologie, CHU Hôtel-Dieu, Nantes, France.
authors: S
authors: S
authors: Barbarot
authors: Service de Médecine Interne, CHU Hôtel Dieu, Nantes, France.
authors: A
authors: A
authors: Néel
authors: Service de Médecine Interne, CHU Hôtel Dieu, Nantes, France.
authors: A
authors: A
authors: Masseau
authors: Service de Médecine Interne, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors: X
authors: X
authors: Puéchal
authors: Service de Rhumatologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
authors: J-E
authors: JE
authors: Gottenberg
authors: Service de Médecine Interne, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors: G
authors: G
authors: Grateau
authors: Service de Médecine Interne, Centre Hospitalier, Niort, France.
authors: C
authors: C
authors: Blanchard-Delaunay
authors: Department of Emergency and Organ Transplantation, Section of Hematology with Transplantation, University of Bari, Bari, Italy.
authors: R
authors: R
authors: Rizzi
authors: Service de Médecine Interne, Centre Hospitalier, Dax, France.
authors: F
authors: F
authors: Lifermann
authors: Service de Médecine Interne, Centre Hospitalier, Valenciennes, France.
authors: X
authors: X
authors: Kyndt
authors: Service de Dermatologie, CHU de Besançon, Besançon, France.
authors: F
authors: F
authors: Aubin
authors: Service de Dermatologie, CHU Saint-Eloi, Montpellier, France.
authors: D
authors: D
authors: Bessis
authors: Service de Dermatologie, Hôpital d'Instruction des Armées Sainte-Anne, Toulon, France.
authors: T
authors: T
authors: Boye
authors: Service de Médecine Interne, Gériatrie et Thérapeutique, CHU de la Timone, Marseille, France.
authors: S
authors: S
authors: Gayet
authors: Department of Dermatology, University of Genova, Genova, Italy.
authors: F
authors: F
authors: Rongioletti
authors: Service de Santé Publique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
authors: E
authors: E
authors: Sauleau
authors: Unité d'Immuno-Hématologie, Hôpital Saint-Louis, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors: J-P
authors: JP
authors: Fermand
authors: Clinique Dermatologique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
authors: D
authors: D
authors: Lipsker
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D019873:Schnitzler Syndrome / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D063189:Symptom Assessment; D055815:Young Adult
keywords: Schnitzler syndrome; auto-inflammatory disease; diagnostic criteria; monoclonal gammopathy; neutrophilic urticarial dermatosis