If you want to isolate an ambient effect to a drawn map or pattern you can use a mask. Just draw your pattern as white against a black background and run it through a math functions: multiply as shown below, white will be the areas glowing... so if you just wanted the palm or fingertips glowing draw your mask with the figure template as a guide. Here's the simple Firefly set up, it's just as easy to use this arrangement amongst a more complex shader set up...