• The main outcome measure will be the change in level of pain, from baseline pain at maximal range of motion (ROM) to pain associated with the procedure, as rated by the child and parent. This approach contrasts with measurement of absolute levels of pain [ Time Frame: Unspecified ] [ Designated as safety issue: No ]
  

• Secondary outcomes will include pain scores during the procedure as follows: 1 during the application of the analgesic agents and 2. at a 24 hours follow-up telephone call. Will be attained by July 2008. [ Time Frame: Unspecified ] [ Designated as safety issue: No ]
  

Procedure: iontophoresis
See Detailed Description.

Research method: This study will be a prospective, randomized clinical trial comparing two methods of delivery of local anesthesia for intra-articular corticosteroids injection (IACI) in children with JIA. There will be two study groups:

1. Children receiving analgesia with subcutaneous lidocaine 2% and EMLA® cream (Rheumatology Division standard of care arm) (n=33)
2. Children receiving analgesia with iontophoresis and EMLA® cream (experimental arm) (n=33).

About one child with JIA per week receives IACI in our institution. To minimize procedural variations in this study, we will select children undergoing knee (by far the most commonly injected joint) IACI by the Pediatric Rheumatology service at BC Children's Hospital. Randomization will be achieved with a Microsoft Access 2003 program. Our primary outcome measures will be change in pain between baseline pain assessed immediately prior to the corticosteroid injection, immediately after the local anesthetic application, and after the corticosteroid injection, using a 10-cm visual analogue scale (VAS, a continuous variable) and the Facial Pain Scale-Revised (FPS-R) scores (a categorical variable). The change in pain will be analyzed using Student's t-test for VAS scores and with Mann-Whitney U test for FPS-R scores. Descriptive statistics for demographic and auxiliary clinical variables will be presented in tables, including mean, range and standard deviation for continuous variables and median, range and percentiles for categorical variables.

Adverse events from EMLA® or iontophoresis will also be recorded (i.e. tingling, redness, blanching, itching, blistering, or pain). Data collected will consist of the child's age, gender, JIA type and duration, number and sites of previous IACIs, and other medications used and will have no patient identifiers (such as name, date of birth, personal health number).