Eli5..if cell turnover occurs every 28-50 days…why do scars/hyperpigmentation remain,

Question

Particularly rolling acne scars and hyperpigmentation on the face.

I understand why deep scars/tattoos remain.

However, thought shallow scars and light sun spots would fad with a few months of cell turnover?

In: 20

Answer 1

only the surface layer, the epidermis, gets replaced every 25-80 days. and that layer is very thin, and basically transparent.

the layer underneath, the dermis, doesn’t have the same amount of turnover.