Yes, this is real vitiligo, can confirm: my dad has the exact same patterns on his hands too. I wanted to make his vitiligo in the Sims 4.
Information in bullet points
Great for both normal and berry sims.
Can be found in Skin Details, near the freckles.
No custom thumbnails.
Disabled for random
Made with Sims 4 Studio
If you'll download this, you'll get a zip with packages for both naturals and unnaturals, so you can choose.