I am designing a small PCB (1"x1") and it will have some DC logic traces (5V and GND) and some high frequency AC power traces (100V 1000Hz 50mA). Are there any special considerations I need to take for isolating these from each other, more so than I do for a typical all-DC board?
A good starting point would be to use UL creepage and clearance guidelines.
If the LVDC and AC don't require galvanic isolation, you can use UL's guideline for functional insulation, which is 40V/mil or 1.6kV/mm. This should eliminate any potential risk of flashover between the HV and LVDC.