Intradermal injections of local and subcutaneous injections of steroid have been used for scar pain. This study compared intradermal dexamethosone and botox and got 25% and 30% relief repectively lasting 4 and 8 weeks respectively.
Scars are considered by some a big cause of chronic pain, even if not tender. Injection, initially, is intradermal (blebbing up scar so blanches). Stats on any success rates are difficult to come by.
Dexamethasone and Botulinum Toxin Type A in the Treatment of Chronic Scar Pain: A Crossover Study.
Marvin Schwartz, DDS (Crown Institute, Pickering, ON, Canada); Brian Freund
Arch Phys Med Rehabil Vol 85, September 2004 Poster 168
- In painful facial or neck scars
- “either dexamethasone (4mg/mL) at 0.5mg/cm of scar tissue or BTX-A (5U per 0.1mL of normal saline) at 2.5U/cm of scar tissue”
- dexamethasone gave 25% relief lasting 4 weeks
- Botox gave 30% relief lasting 8 weeks
Comment – results are poor and suspect would have been better if local was added to dexamethasone. I had been using 5% lidocaine into scars with benefit but got a rash in one case – I suspect from the phenol perservative I used. I would suggest pain lidocaine intradermal first, kenalog steroid injection, subcutaneous second, and maybe botox thereafter if not response. Can’t imagine doing this without skin stretching myofascial release therapy with it.
addendum – recent presentation by Dr. Helene Bertrand at the Canadian Association of Orthopaedic Medicine (CAOM) 2015 in Vancouver found that D5W injection into lumbar scars did not work well and that it took repeated triamcinolone injections at least 5-7 times to get relief and that some atrophy might result from it ( It was suggested Z-tracting might help (push skin to one side while injecting then release when withdrawn makes it so material can’t tract back). It does appear it takes multiple injections to get good results…