title: Ultrasound examination of extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis immunization in preschool-aged children.
abstract: OBJECTIVE
  The aim of this study was to determine the site, extent, and resolution of tissue involvement when extensive limb swelling occurred in the injected limb for children who received diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine at 4 to 6 years of age.
  
  
  METHODS
  Children who had experienced an injection site reaction at 18 months of age were assigned randomly to receive an intramuscular injection of either reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine or diphtheria-tetanus-acellular pertussis vaccine between 4 and 6 years of age. Children who developed extensive limb swelling were recruited for assessment by clinical examination; ultrasound studies of the affected and opposite (control) arms were performed 24 to 48 hours after immunization and 48 to 96 hours later.
  
  
  RESULTS
  Twelve children with extensive limb swelling were enrolled in the study. Ultrasound examinations demonstrated swelling of both the subcutaneous and muscle layers of the vaccinated arm. Ultrasound assessment showed that the swelling exceeded the clinical measurements of skin redness and swelling. Subcutaneous and muscle tissues expanded to 281% and 111% of the tissue thicknesses of the control arm, respectively. Repeat ultrasound examinations after 48 to 96 hours showed considerable resolution of muscle swelling, compared with subcutaneous tissue swelling. There was no significant difference in the extent of swelling detected between children who received diphtheria-tetanus-acellular pertussis vaccine and those who received reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine.
  
  
  CONCLUSIONS
  Extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content booster immunizations involved swelling of subcutaneous and muscle tissues with swelling and duration more marked in subcutaneous tissue.
authors.affiliation: University Department of Paediatrics, Women's and Children's Hospital, 72 King William Rd, North Adelaide 5006, South Australia, Australia. helen.marshall@adelaide.edu.au
authors.forename: Helen Siobhan
authors.initials: HS
authors.lastname: Marshall
authors.forename: Michael Steven
authors.initials: MS
authors.lastname: Gold
authors.forename: Roger
authors.initials: R
authors.lastname: Gent
authors.forename: Patrick John
authors.initials: PJ
authors.lastname: Quinn
authors.forename: Lino
authors.initials: L
authors.lastname: Piotto
authors.forename: Michelle Frances
authors.initials: MF
authors.lastname: Clarke
authors.forename: Donal Muir
authors.initials: DM
authors.lastname: Roberton
mesh_terms: D000942:Antigens, Bacterial; D001132:Arm / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000009:adverse effects*; D004311:Double-Blind Method; D004487:Edema / Q000139:chemically induced; D005260:Female; D006801:Humans; D007117:Immunization, Secondary / Q000009:adverse effects; D008297:Male; D011446:Prospective Studies; D012720:Severity of Illness Index; D014463:Ultrasonography
chemical_list: D000942:Antigens, Bacterial; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines