title: Hypersensitivity reaction against patent blue during sentinel lymph node removal in three melanoma patients.
abstract: BACKGROUND
  In order to identify the sentinel lymph node (SLN) in melanoma patients intradermal injection of a radiocolloid tracer and a blue dye are commonly used. Life-threatening side effects such as allergic reactions to the injected dye have been described. We report 3 cases with systemic allergic reactions.
  
  
  METHODS
  Three patients suffering from systemic reactions such as hypotension and rash during SLN biopsy were tested for sensitisation against patent blue and methylene blue with skin prick, scratch, and intradermal test.
  
  
  RESULTS
  All 3 patients showed positive skin tests to patent blue confirming allergic reaction to the injected dye. In addition, all patients showed positive skin tests with methylene blue indicating immunologic cross-reactivity between patent blue and methylene blue.
  
  
  CONCLUSIONS
  Although allergic reactions to blue dye during SLN biopsy are rare, they may be life threatening. It is important that the attending anesthetist is aware of this.
authors.affiliation: Department of Dermatology, University of Bern, Inselspital, 3010 Bern, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Keller
authors.forename: Nikhil
authors.initials: N
authors.lastname: Yawalkar
authors.forename: Christiane
authors.initials: C
authors.lastname: Pichler
authors.forename: Lasse R
authors.initials: LR
authors.lastname: Braathen
authors.forename: Robert E
authors.initials: RE
authors.lastname: Hunger
mesh_terms: D000328:Adult; D000368:Aged; D004396:Coloring Agents / Q000009:adverse effects; D005076:Exanthema / Q000209:etiology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007022:Hypotension / Q000209:etiology; D008197:Lymph Node Excision / Q000009:adverse effects*; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000556:secondary* / Q000601:surgery*; D008751:Methylene Blue / Q000009:adverse effects; D012189:Retrospective Studies; D012394:Rosaniline Dyes / Q000009:adverse effects*; D012878:Skin Neoplasms / Q000473:pathology; D012882:Skin Tests; D013610:Tachycardia / Q000209:etiology; D014581:Urticaria / Q000209:etiology
chemical_list: D004396:Coloring Agents; D012394:Rosaniline Dyes; C008769:sulfan blue; D008751:Methylene Blue