title: Allergic complications from orthopaedic joint implants: the role of delayed hypersensitivity to benzoyl peroxide in bone cement.
abstract: BACKGROUND
  Orthopaedic implants and osteosynthesis materials are increasingly being used. Complications include mainly physical-mechanical problems and infections. Uncommonly, an allergic reaction towards an alloy metal or a bone cement component has been implicated. Potential bone cement allergens include acrylates, benzoyl peroxide, N,N-dimethyl-p-toluidine, and gentamicin. Typical symptoms are pain, swelling, inflammatory skin reactions, implant loosening, and fistula formation.
  
  
  OBJECTIVE
  To report on 5 patients with complications from a knee or a shoulder joint implant in whom a relevant sensitization to benzoyl peroxide was shown.
  
  
  METHODS
  Patch tests were performed with the European baseline series, an extended metal series, and a bone cement series. Patch tests with benzoyl peroxide were performed twice in all patients. A bone cement-free replacement was chosen in sensitized patients.
  
  
  RESULTS
  In 4 patients sensitized to benzoyl peroxide, a bone cement-free replacement resulted in a considerable decrease or disappearance of pain and swelling, and complete clearing of cutaneous symptoms.
  
  
  CONCLUSIONS
  Components of bone cement, such as benzoyl peroxide, may rarely cause allergic complications. However, because of the irritant potential of these substances, careful performance, reading and interpretation of the patch tests is required.
authors.affiliation: Allergy Unit, Department of Dermatology, University Hospital Basel, University of Basel, CH-4031 Basel, Switzerland. andreas.bircher@unibas.ch
authors.forename: Andreas
authors.initials: A
authors.lastname: Bircher
authors.forename: Niklaus F
authors.initials: NF
authors.lastname: Friederich
authors.forename: Walter
authors.initials: W
authors.lastname: Seelig
authors.forename: Kathrin
authors.initials: K
authors.lastname: Scherer
mesh_terms: D000328:Adult; D000368:Aged; D001585:Benzoyl Peroxide / Q000009:adverse effects* / Q000032:analysis; D001843:Bone Cements / Q000009:adverse effects* / Q000737:chemistry; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D005260:Female; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000139:chemically induced* / Q000175:diagnosis; D007595:Joint Prosthesis / Q000009:adverse effects*; D007720:Knee Prosthesis / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010328:Patch Tests; D012785:Shoulder Joint / Q000601:surgery
chemical_list: D001843:Bone Cements; D001585:Benzoyl Peroxide