Investigators will collect blood specimens from the participating patients and then blood samples will be centrifuged in order to collect platelet-rich plasma which is going to be injected in the atrophic acne scars. A split-face design is going to used in this randomized controlled trial. In the control side of the face, micro-needling to the skin will occur using a specific tool (Dermapen).

Atrophic acne scar is a common problem with a challenging treatment. Platelet-rich plasma (PRP) is an autologous preparation of platelets in concentrated plasma that may be beneficial in the treatment of atrophic acne scars by promoting collagen deposition.

Skin needling is a technique that uses a sterile micro needles to puncture the skin and release growth factors. The combination of skin needling and PRP could enhance the efficacy of both modalities.

Inclusion Criteria:

• Atrophic acne scars on both sides of the face

Exclusion Criteria:

• patients with active acne, herpes labialis, or bacterial infection; warts on the face, actinic keratosis, or skin cancer
• systemic retinoids intake in the previous 6 months,
• diabetes, pregnancy, history of keloidal scarring; or patients with severe systemic illness or malignancy
• patients on anticoagulant therapy or aspirin or have a coagulation issue,
• patients with hemoglobin less than 10g\dl or platelet less than 105 micron\l
• any previous procedures for acne scar within the last 6 months