title: Patch testing in oral lichenoid lesions of uncertain etiology.
abstract: BACKGROUND
  The benefit of patch testing patients with oral lichenoid lesions (OLL) is still debated.
  
  
  OBJECTIVE
  We assessed the results of patch testing in patients with multiple amalgams and multiple OLL, where the etiology of the oral mucosal disease was unclear.
  
  
  METHODS
  Patients referred from an oral medicine clinic were patch tested to the British Society of Cutaneous Allergy standard series, dental and materials series, and, in 1 patient, the dental methacrylate series also. Patients' responses to amalgam removal were assessed during a mean follow-up of 2.6 (range, 0-4.75) years.
  
  
  RESULTS
  Thirty-one patients with OLL were referred for patch testing. Ten (32%) patients tested positively to mercury. Eight patients with positive reactions to mercury had amalgam removal, with complete or partial resolution of the OLL in all cases (100%).
  
  
  CONCLUSIONS
  Patients with OLL of unclear etiology adjacent to large amalgam restorations should be investigated for delayed contact hypersensitivity. Removal of amalgams in patients with positive patch test reactions to mercury results in improvement or resolution of the OLL in most patients.
authors.affiliation: From the *Charles Centre, Department of Dermatology, St Vincent's University Hospital; and †Dublin Dental University Hospital, Ireland.
authors.forename: Maeve
authors.initials: M
authors.lastname: Lynch
authors.forename: Aisling
authors.initials: A
authors.lastname: Ryan
authors.forename: Sheila
authors.initials: S
authors.lastname: Galvin
authors.forename: Stephen
authors.initials: S
authors.lastname: Flint
authors.forename: Claire M
authors.initials: CM
authors.lastname: Healy
authors.forename: Niamh
authors.initials: N
authors.lastname: O'Rourke
authors.forename: Kathleen
authors.initials: K
authors.lastname: Lynch
authors.forename: Sarah
authors.initials: S
authors.lastname: Rogers
authors.forename: Paul
authors.initials: P
authors.lastname: Collins
mesh_terms: D000328:Adult; D000368:Aged; D000485:Allergens / Q000009:adverse effects*; D015331:Cohort Studies; D003723:Dental Amalgam / Q000009:adverse effects*; D003877:Dermatitis, Contact / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D020878:Device Removal; D005260:Female; D006801:Humans; D017512:Lichenoid Eruptions / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D008297:Male; D008628:Mercury / Q000009:adverse effects*; D008875:Middle Aged; D009059:Mouth Diseases / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D009061:Mouth Mucosa; D010328:Patch Tests; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000485:Allergens; D003723:Dental Amalgam; D008628:Mercury