Why do pimples scar?

Acne Scars: Scarring occurs when there is damage to the deeper layers of the skin. In acne, scarring/dimpling can result from inflammation, cysts, & nodules deep in the skin, or as a result of trauma from squeezing lesions. Post-inflammatory hyperpigmentation (pih) is when a dark or reddish flat spot remains after a pimple has cleared. Unlike true scars, pih can fade with time (months) & sun protection.

Cause injury: Any injury to the dermis will cause permanent scarring.