Hi Dr. Kelly: My friend insists on using numbing cream when she gets Botox, but I never need it. Why is that?
Great question, with a complicated answer. Numbing cream is a local anesthetic that is applied to the skin to diminish the sensation of needle sticks. There are a variety of formulations and strengths but the one we use in the office consists of Benzocaine, Lidocaine and Tetracaine. Lidocaine is the same drug that your dentist uses to numb you before a dental procedure. Instead of injecting it, we spread it on the skin and it is absorbed.
So why do some people insist on using numbing cream when getting Botox while others don’t need it? Because there are many variables that determine how pain is perceived.
First of all, pain perception is individualized. What one person considers painful may be trivial to another. Studies have shown the following: Women perceive pain more than men. Depression and anxiety can make patients more sensitive to pain. Athletes are able to withstand pain more than people who don’t exercise. People who smoke or are obese are more sensitive to pain as well.
Societal norms can play a role. When I traveled to Latin America to perform cleft lip surgery, the post-op wards were incredibly loud with both babies (and mothers) crying. In China, you could walk into the nursery after surgery and it was so quiet, you could hear a pin drop. Patient expectations and accepted behavior obviously play a big role.
Finally, science has found differences in brain structures among those who perceive more pain. MRIs show patients who are more sensitive to pain have less gray matter in specific areas of the brain related to pain perception. Redheads are also more sensitive to pain and have a specific gene, MC1R, that controls a group of pain receptors in the brain.
At the end of the day, we all perceive pain differently for a variety of reasons. Some people just experience more pain with injections than others. Understand that numbing cream can make that experience more tolerable for your friend, so be supportive and help her get rid of those wrinkles!