Does Isaac's damage affect the damage of followers?

[Mister Sparklz]

I'm trying the Family Man challenge and I'd like to know if i should bother with damage increases, or if they're worthless. Thanks in advance for help given

[Elovan]

Of the familiars you start with, only the flies from Rotten Baby scale with your damage. There are a few other familiars that scale with your damage, but you'd have to luck into finding them.

[Icedfate]

if you have afterbirth, the incubus fires the same tears that you do, so despite being blindfolded, you will get the same effect as your normal tears. In addition, BFFs works on the incubus, scaling his damage up even higher.

[SonicDen220]

Only Rotten Baby, Incubus and Fate's Reward.