What would cause injection site soreness after Botox?

Thank you for your question. Every time you have a Botox treatment it can feel different depending on many variables. Sometimes soreness can be attributed to personal factors including stress levels or diet. Discomfort can also be due to injection technique or the individual needle. It may have been a one time occurrence. In any case, it does not seem to be something you have to worry about for the time being. Consider discussing your concerns with your injector at your next treatment. Best,  

Injection site tenderness, pain and redness is pretty common and usually lasts less than a few days. I would suspect that this would improve over the next few days. If it doesn't, or you have any additional concerns, I would recommend returning to the physician who performed the injections and discuss this with them. 

This is an uncommon complaint but, personally, I've felt mild discomfort after Botox injections. The fact your skin looks normal is encouraging. If this is not improving daily, discuss with your injector. In the meantime, ice and anti-inflammatory medications can be very helpful. I hope this information is helpful for you.Stephen Weber MD, FACSDenver Facial Plastic Surgeon