title: Nickel sensitization in patients with gastro-esophageal reflux disease.
abstract: BACKGROUND
  Gastro-esophageal reflux disease (GERD) leads to frequent medical visits, and available therapies fail in up to 40% of patients. Food allergies may be involved in GERD pathogenesis; however, allergens other than food have received little attention. Nickel allergy is common in the general population and some high-nickel foods are associated with GERD. However, the potential relationship between nickel allergy and GERD remains unaddressed.
  
  
  OBJECTIVE
  This study aimed to evaluate the prevalence of nickel sensitization in patients with and without GERD and to compare clinical and demographic features.
  
  
  METHODS
  This prospective, multicenter study included 210 adult GERD patients and 140 patients without GERD who presented at the general practitioner. All GERD patients had undergone treatment with proton pump inhibitors and upper digestive endoscopy within the previous five years. Demographic and clinical data were collected by questionnaire and patients underwent a nickel patch allergy test.
  
  
  RESULTS
  Patients with and without GERD presented similar characteristics, with the exception of nickel sensitization, which was significantly more prevalent among GERD patients than controls (39.5% vs. 16.4%; p = 0.001). Nickel-positive GERD patients were more frequently female (90.4% vs. 65.4%, p = 0.003) and asthmatic (18.1% vs. 4.7%; p = 0.038), compared to nickel-negative GERD patients. At six-month follow-up, most of the patients, with or without nickel sensitization, reported improved symptoms without differences in drug prescription.
  
  
  CONCLUSIONS
  Nickel sensitization is particularly prevalent in GERD patients seen in general practice. Whether allergies other than food allergy play a role in GERD remains to be elucidated.
authors.affiliation: Department of Digestive Diseases and Internal Medicine, University of Bologna, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Stanghellini
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Tosetti
authors.affiliation: Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Rende, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Benedetto
authors.affiliation: Allergist, Vibo Valentia, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Condoluci
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Rudi
authors.initials: R
authors.lastname: De Bastiani
authors.affiliation: Department of Digestive Diseases and Internal Medicine, University of Bologna, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Cogliandro
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Tecla
authors.initials: T
authors.lastname: Mastronuzzi
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: De Polo
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Di Mita
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Napoli
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Enzo
authors.initials: E
authors.lastname: Ubaldi
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Nebiacolombo
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Carmelo
authors.initials: C
authors.lastname: Cottone
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Ignazio
authors.initials: I
authors.lastname: Grattagliano
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Zamparella
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Baldi
authors.affiliation: General Practitioner and Gastroenterologist, Italian Group for Primary Care Gastroenterology (GIGA-CP), Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Sanna
keywords: Gastro-esophageal reflux disease; allergy; functional gastrointestinal disorders; nickel; symptoms