My local mikvah attendant always puts out her hand after I have come out of the pool and asks me to touch her. Do you know the reason for this custom? I am too shy to ask her...
Emerging from the mikvah you have just attained a heightened level of purity and holiness. As such, it is important to seal, so to speak, that purity by ensuring that the first things you see and touch are holy. Thus, many are accustomed to touch the mikvah attendant – another holy Jewish person – upon emerging from the water.
In fact, a story is told of a woman in Communist Russia who went to great lengths and personal risk to use a proper mikvah. Once, as she left the mikvah, an impure animal jumped out at her. She promptly turned around and went back to immerse again!
Malkie Janowski for Chabad.org