Is the combination of water and medical skin laser dangerous?
Many physicians apply numbing agent creams/ointments such as Lidocaine+Prilocaine or Benzocaine+Lidocaine+Tetracaine (BLT) preparations topically some 30 minutes before laser hair removal treatments, often with some non absorbing pressure patch on it.
There might be cases when a patient might prefer an injection of these materials instead topical administration.
Topical numbing agents (especially non-water-containing oily ointments) get absorbed by diffusion but injections normally contain watery solutions (as far as I know, at least).
I speculate that because laser is heat and too much water especially with big/round laser beams can cause injected water to "boil", this might be a problem and should therefore be avoided.