A Human Repeat Patch Test Study

Objective:

This poster describes the results of a study that was undertaken to evaluate an antimicrobial dressing with soft silicone adhesive (containing chlorhexidine and silver) for the induction of contact sensitization by repetitive applications to the skin of normal healthy volunteers in a repeated insult patch test (RIPT).

Methods:

This was a single-centre randomized study. A total of nine applications of test dressings were applied over a 3-week period to the back of 216 volunteers. Dressings were worn for 48 or 72 hours. Following a 2-week Rest Phase after the completion of the Induction Phase of the study, a challenge exposure of a single 48-hour application of dressings to a naïve site was done. Skin evaluations were carried out post-removal of the test dressings. Dressing adhesion and pain upon removal assessments were carried out at each 72 hour study visit following first application.

Results:

Overall there was no evidence of induced contact sensitisation for the antimicrobial dressing with soft silicone adhesive and its control (a non-antimicrobial dressing with soft silicone adhesive) or a comparison challenge dressing (an antimicrobial film dressing with a central chlorhexidine gel pad and acrylic adhesive border). The test dressings with the soft silicone adhesive exhibited significantly less irritation than the adhesive border of the film dressing with a central chlorhexidine gel pad. Both dressings with soft silicone adhesive elicited very low pain scores, which were on average 10x lower than those of the film dressing with the acrylic adhesive border.

Conclusion:

The antimicrobial dressing with soft silicone adhesive showed no potential for contact sensitization in this study and exhibited low skin sensitization. The use of soft silicone adhesive results in good adhesion with low pain experienced upon dressing removal.