Local infiltration of 1% lidocaine provides excellent anesthesia for the skin of the perinuem.
The injection is best made just below the skin, raising just a small weal to visualize the extent of the infiltration.
There is no need to infiltrate deep into the perineal tissues as there are very few nerves there. The skin, however, is very sensitive.
Watch your total dose of lidocaine. The maximum safe limit for 1% lidocaine (without risking toxicity) is 50 cc.