If this is for a commercial product it will need to pass ESD testing and all user-accessible inputs/contacts will be subjected to a contact discharge test.
If there is a relatively large capacitance behind those contacts you might get away without an ESD protection diode (though I would still put one in), but otherwise you almost certainly need an ESD protection diode. The ESD diode should be placed as close as possible to the external input/contact and a series resistor should be added between the ESD diode and the rest of the circuit to protect it from the high clamping voltage of the ESD diode.