Why no Neosporin etc. on a sutured surgical incision to prevent infection?

[BarryEE]

A few days ago I had three procedures; Decompression of my Ulnar nerve, trigger finger repair, and a carpal tunnel repair (all same side). All procedures were done at the same time and, from my perspective, it was a medical non-event, just a big inconvenience due to essentially no use of my right arm for almost two weeks.

The surgeon was very adamant about not applying anything but a bandage over the three sutured incisions. When I told her I was using Neosporin she firmly stated not to use it and keep the incision dry.

Although there is now no sign of infection I intend to keep it that way because after 36 hours the three incisions were still weeping a bit and therefore still present an open port, albeit small, for infection. I am not following her instructions about using nothing under the bandages as that seems to not comprehensively address doing everything possible to avoid an infection. Instead of Neosporin I am now applying Betadine as that dries within a minute or so but I do not believe it continues to provide any barrier once dry whereas Neosporin ointment probably does.

Of course, I now want to understand why it is not prudent to apply an antiseptic to a not fully sealed incision. No matter how careful I am when applying a bandage, I cannot preclude any chance of inadvertently contaminating the incision site.  I understand the body's immune system is the ultimate defense and will probably successfully deal with a small contamination but post surgical infections, even in a hospital environment, still happen. Also, what are the consequences of applying Neosporin (or Betadine)? It seems to me an incision that takes slightly longer to heal, if that is the consequence, is a small price to pay to preclude an infection.

I would certainly appreciate help understanding this. It is very frustrating and disconcerting to have a physician firmly give instructions that are counter intuitive and not be able to have any real discussion to understand it. At least for me, this makes compliance difficult and that might very well not be in my best interests.

Thank you.