title: Results of patch testing in patients diagnosed with oral lichen planus.
abstract: BACKGROUND
  Oral lichenoid lesions (OLLs) resemble oral lichen planus (OLP) but develop secondary to various underlying causes. The role of contact allergy in precipitating and/or perpetuating OLL is well documented but remains controversial.
  
  
  OBJECTIVE
  To help elucidate the association of contact allergy and OLL, we reviewed patch-test readings in patients diagnosed with OLP-like lesions.
  
  
  METHODS
  We retrospectively reviewed patients diagnosed with OLP-like lesions who had patch tests performed between January 1, 2006, and December 31, 2007.
  
  
  RESULTS
  Patch tests were performed on 24 patients with a histopathologic and/or clinical diagnosis of OLP. Of these, 16 (67%) had positive patch-test readings. At least eight (50%) of these patients had clinically relevant reactions. Ten of the 16 patients (63%) had reactions to metals. In most of these patients, troublesome areas tended to localize adjacent to metallic dental restorations. Of the nine patients (56%) who had reactions to fragrances, flavorings, gallates, and/or diallyl disulfide, the majority improved after avoiding these allergens.
  
  
  CONCLUSIONS
  Our findings support the notion that contact allergy may underlie the pathogenesis of OLL and that allergen avoidance may result in amelioration of disease.
authors.affiliation: Division of Dermatology, University of Toronto, Sunnybrook Health Science Center, Toronto, ON, Canada.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lomaga
authors.forename: Shely
authors.initials: S
authors.lastname: Polak
authors.forename: Miriam
authors.initials: M
authors.lastname: Grushka
authors.forename: Scott
authors.initials: S
authors.lastname: Walsh
mesh_terms: D000328:Adult; D000368:Aged; D003877:Dermatitis, Contact / Q000150:complications* / Q000175:diagnosis; D005260:Female; D006801:Humans; D017676:Lichen Planus, Oral / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D012189:Retrospective Studies