Since friendly fire (both ways) is on by default with no option in vanilla to disable, your options are either to increase your magic resistances to prevent receiving AOE or splash damage from follower, or if that is not they answer you are looking for, your only recourse is to resort to modding & console commands.
Looking around NEXUS it seems that there is no specific mod that prevents your from receiving damage from a companion, some rumours suggest that this mod available on NEXUS No Friendly Fire has that option, the description on NEXUS however does not credit that.
However the suggestion
found here Useful Console Commands : Elder Scrolls Skyrim apparently
Turns off friendly fire for your target, or you.
Your mileage may vary as
sifh is the "set ignore friendly hits" function, making the target not attack back if you attack them.
However if you can target yourself or make your character the object of that command, hypothically it might prevent you from taking damage if you are to believe skyrimelder
To avoid dealing friendly damage to companions from AOE or splash damage, there is an ability called Companion's Insight found in The Elder Scrolls V: Dragonborn which has the following description
"Your attacks, shouts, and destruction spells do no damage to your followers when in combat."
Followers may still be wounded from Storm Call, Chain Lightning, Wall of Storms, Unrelenting Force, etc