Hypopigmentation

If you google vitiligo treatment there's some helpful info. Especially recommending using high factor sunscreen as depigmented skin can burn easily.

My mother had white patches on her arms. I dont know what caused it nor if she had any treatment, but that was called vitiligo.

I have family members with Vitiligo, Lichen Sclerosis, thyroid issues. The one with Lichen Sclerosis also has small white patches on their arms but not vitiligo. She was told LS and the small white patches often occur together. The one with Vitiligo has larger white patches over his neck, arms and face. He can put a cover up cream on but doesn't bother any more as it looked odd. Doctors are much quicker with diagnosing Vitiligo now so I'd have thought they would have said it was that if suspected. There's a lot more clinical trials for potential treatments now Sunscreen as HelterSkelter said, is essential. So hopefully if it's because of over-squeezing a spot then hopefully it will recover.

The reason I mentioned all of the above conditions is because they are autoimmune conditions and apparently genetically connected.

From what I read, this all depends on the depth of skin damage, and whether the pigment-producing cells (melanocytes) have been temporarily stunned or permanently destroyed. From what you describe happened, I would say this is more likely to be temporary. It may just need more time (and patience) for the cells to start to making melanin again.