Cleansing Flame

You take a ball of fire in your hand, and use it to burn away any toxins afflicting yourself or another creature. The targeted creature takes 1d6 fire damage, and you immediately negate any poisons affecting it, as well as ending the poisoned condition. If you attempt to use this spell on an unwilling creature, you must make a melee spell attack against it. 

This old pyromancy is very common among the pyromancers of the great eastern swamps; many of the native creatures are known for slow-acting poisons and venoms that bring terrible pain and slow death. It is unsurprising that most would choose to burn themselves to stave off such a demise.