title: T-cell reaction to local anaesthetics: relationship to angioedema and urticaria after subcutaneous application--patch testing and LTT in patients with adverse reaction to local anaesthetics.
abstract: BACKGROUND
  Local anaesthetics are known to elicit T-cell reactions after epicutaneous application, namely contact dermatitis. In addition, adverse reactions like urticaria and angioedema are rather common after submucosal or subcutaneous injection. The pathogenesis of these side-effects, which appear frequently hours after application, is unknown, but thought to be not immunoglobulin E-mediated, since immediate skin tests are mostly negative.
  
  
  OBJECTIVE
  We investigated whether patients who developed urticaria and angioedema after subcutaneous application have a T-cell sensitization to local anaesthetics, which might be responsible for the symptoms.
  
  
  METHODS
  Twenty patients with generalized and/or local cutaneous reactions after LA were examined with intradermal testing using a standard panel of six LAs and patch testing using between seven and nine LAs in vaseline and four LAs in PBS. In 10 patients, a lymphocyte transformation test (LTT) was performed.
  
  
  RESULTS
  Only 2/20 patients had an immediate skin reaction (positive intradermal test), whereas 6/20 patients had a positive delayed skin reaction (positive patch test). In 6/10 subjects the LTT was positive.
  
  
  CONCLUSIONS
  Delayed appearance of urticaria and angioedema after subcutaneous application of local anaesthetics may be related to a T cell- mediated sensitization, which might be detected by patch testing or LTT.
authors.affiliation: Institute of Immunology and Allergology, University Hospital, Bern, Switzerland.
authors.forename: C E
authors.initials: CE
authors.lastname: Orasch
authors.forename: A
authors.initials: A
authors.lastname: Helbling
authors.forename: M P
authors.initials: MP
authors.lastname: Zanni
authors.forename: N
authors.initials: N
authors.lastname: Yawalkar
authors.forename: Y
authors.initials: Y
authors.lastname: Hari
authors.forename: W J
authors.initials: WJ
authors.lastname: Pichler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000009:adverse effects* / Q000276:immunology; D000799:Angioedema / Q000139:chemically induced* / Q000276:immunology*; D002648:Child; D005260:Female; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D013601:T-Lymphocytes / Q000276:immunology*; D014581:Urticaria / Q000139:chemically induced* / Q000276:immunology*
chemical_list: D000779:Anesthetics, Local