Acne scars represent a frequent complication of moderate/severe acne and may negatively impact on psychosocial and physical well-being of acne patients. Several types of acne scars have been classified and the same patient is likely to have more than one type. Each type can be treated with varying degrees of success. The main acne scars are the following:

Atrophic or Depressed Scarring:

• Ice pick: An ice pick scar has a wide shaft that narrows down to the tip. It resembles a hole that's wide at the top and narrows to a point as it goes deeper into the skin. Such an indentation is common and one of the most challenging scars to heal. This scar is more frequent on forehead and upper cheeks, where skin is thinner.
• Rolling: These scars are typically found on the lower cheeks and jaw, where skin is thicker. The indents have sloping edges that makes the skin look uneven and wavy.
• Boxcar: Boxcar scars are indents that have sharper edges. Those edges go down deep into the skin. These scars are common on the lower checks and jaw.

Open label clinical trial, conducted by 1 center under dermatological control.

Primary aim of the study is to evaluate the efficacy and the safety of the deep injection of HCC_45 in acne scars of the face (ice picks, rolling, boxcars).

Secondary endpoint is self-assessment questionnaire regarding treatment efficacy and tolerance.

HCC_45 is a resorbable medical device 2 ml nonpyrogenic pre-filled syringe, containing 2 ml of hyaluronic acid for intradermal use. The principal component of the medical device is Hyaluronic Acid of non-animal origin, produced by bacterial fermentation.

Inclusion Criteria:

• caucasian subjects of both sexes;
• age >18years
• asking for acne scars treatment;
• presenting acne scars (ice picks, rollings, boxcars);
• available and able to return to the study site for the post-procedural follow-up examinations;
• agreeing to present at each study visit without make-up;
• accepting to not change their habits regarding food, physical activity, make-up use, face cosmetic and cleansing products;
• accepting not to expose their face to strong UV irradiation (UV session, or sun bathes) during the entire duration of the study, without appropriate sun protection;
• accepting to sign the Informed consent form.

Exclusion Criteria:

• Dependent on the volunteers' characteristics:
• smokers;
• performing in the 6 month before the trial beginning HA injections, radiofrequency treatment, toxin treatment;
• contraindication or know allergy to the devices' components or to the treatment;
• participation in a similar study actually or during the previous 3 months
• known pregnancy
• occurrence of pregnancy during the study
• Dependent on a clinical condition: Dermatological disease:
• Dermatitis;
• presence of cutaneous disease on the tested area,different from those under study
• recurrent facial/labial herpes;
• clinical and significant skin condition on the test area (e.g. active eczema, psoriasis, severe rosacea, scleroderma, local infections and severe acne).
• Dependent on a clinical condition: General disease:
• Diabetes, coagulation disorders, connective tissue disorders, lipodystrophy or other systemic disease;
• HIV and/or immunosuppressive disease;
• cancerous or precancerous lesions in the either right or left midface;
• severe allergies manifested by a history of anaphylaxis, or history or presence of severe multiple allergies;
• alcohol or drug abusers;
• Dependent on a pharmacological treatment:
• Anti-inflammatory drugs, anti-histaminic, topic and systemic corticosteroids, narcotic, antidepressant, immunosuppressive drugs (with except of contraceptive or hormonal treatment starting more than 1 year ago);
• assumption of drugs able to influence the test results in the investigator opinion.

The use of other drugs, not mentioned above, can be authorized by the Investigator. The trade name, the dosage, the start and stop date of the therapy will be reported on Case Record Form (CRF).