Acne vulgaris is a common cutaneous inflammatory disorder of the pilosebaceous unit, which runs a chronic course. The condition commonly manifests with papules, pustules, or nodules primarily on the face, although it can also affect the upper arms, trunk, and back. The pathogenesis of acne vulgaris involves the interaction of multiple factors that ultimately lead to the formation of its primary lesion, which is known as "comedo".
Because of its long duration and exposure to affected areas, acne is associated with a major deterioration in a patient's quality of life and well-being .
Up to 95% of acne sufferers have some degree of acne scarring, with 30% reporting severe acne scarring. Scarring from acne is common when medical care is delayed or is not sufficient, although it can also occur even when treatment is adequate .
About 90% of acne scars are related with collagen loss (atrophic scars), whereas the remaining 10- 20% show collagen gain (keloidal or hypertrophic scars). Resulting from the contraction of fibrous tissue, atrophic scars appear as depressions. Atrophic acne scars can be classified into three distinct types: boxcar, icepick, and rolling.