Evaluation, Prevention, and Management of Acne Scars: Issues, Strategies, and Enhanced Outcomes

December 2018 | Volume 17 | Issue 12 | Supplement Individual Articles | 44 | Copyright © December 2018

Gabriella Fabbrocini MD and Sara Cacciapuoti MD

Department of Clinical Medicine and Surgery, Section of Dermatology, University of Naples Federico II, Naples, Italy

gene expression by increasing secretion of IL-6. The best results achieved for acne scars include five sequential sessions of 70% glycolic acid every two weeks. The disadvantages of GA are penetration often not uniform, mandatory neutralization, and high risk of overpeel if the time of application is too long or if the skin is inflamed. Persistent hyperpigmentation and irritation are the most common side effect of this chemical agent.Jessner’s solution (JS): JS is a combination of salicylic acid, resorcinol, and lactic acid in 95% ethanol, able to induce corneocyte detachment and subsequent desquamation of the stratum corneum, enhancing penetration of other agents. The depth of the peel depends on the number of coats of solution applied. Different patients may require different number of coats to achieve the same level of peel. This is because the penetration of the solution depends on a number of factors, including the preparation of the skin, the thickness of the corneum, and the sensitivity of the skin. The advantages of JS are that the peel is very superficial and safe, and rarely goes deeper than one would expect. Scaling, irritation, burning sensation, and persistent hyperpigmentation are the most frequent side effects of this chemical agent.Pyruvic acid (PA): PA presents keratolytic, antimicrobial, and sebostatic properties, as well as the ability to stimulate new collagen production and the formation of elastic fibers. The use of 40 to 70% pyruvic acid has been proposed for the treatment of moderate acne scars. The advantages of pyruvic acid are the homogeneous penetration with uniform erythema, mild desquamation, short postoperative period, and the possibility of use for all skin types. Disadvantages include intense stinging and burning sensation, mandatory neutralization, and irritating vapors for the upper respiratory mucosa.Salicylic acid (SA): SA is one of the best peeling agents for the treatment of acne scars. It is a beta hydroxy acid. SA removes intercellular lipids that are covalently linked to the envelope surrounding cornified epithelioid cells. The most efficacious concentration for acne scars is 30% in multiple sessions, 3 through 5 times, every 3 through 4 weeks.15 The side effects of salicylic acid peeling are mild and transient. The advantages of salicylic acid are an established safety profile in all skin types, post-inflammatory hyperpigmentation or scarring are very rare, and for this reason it is used to treat dark skin. The disadvantage of salicylic acid is the intense stinging and burning sensation.Trichloroacetic acid (TCA): TCA causes protein denaturation, the so-called keratocoagulation, resulting in a readily observed white frost. The degree of the frosting correlates with the depth of solution penetration on the basis of different concentrations. TCA in a percentage of 10%–20% results in a very light superficial peel with no penetration below the stratum granulosum;a concentration of 25%–35% produces a light superficial peel with diffusion encompassing the full thickness of the epidermis; 40%–50% can produce injury to the papillary dermis, and finally, greater than 50% results in injury extending to the reticular dermis. The use of TCA in concentrations greater than 35% should be avoided. It can be preferred in some cases of isolated lesions or for treatment of isolated ice-pick scars (TCA CROSS).16 The advantages of TCA are low cost, uniformity of application, and the ability to evaluate the penetration by the color of frost. The disadvantages include stinging and burning sensation during the application. High concentrations are not recommended in skin types V to VI due to the potential for hypo/hyperpigmentation.Phenol: Phenol is a deep peel that can improve atrophic acne scars. However, it requires sedation and cardiovascular monitoring and it is not recommended in skin types IV to VI. Deep peels as phenol are more rarely used because of the downtime required for healing and the potential for complications and adverse events.Skin Microneedling or Percutaneous Collagen Induction Skin needling is a dermatologic treatment procedure performed to achieve percutaneous collagen induction (PCI), which is effective in improving depressed acne scarring. At first, facial skin must be cleansed, then a topical anaesthetic is applied and left for 60 minutes. The skin needling procedure is achieved by rolling a preformed tool comprising multiple thin microneedles on the cutaneous areas affected by acne scars: the skin is punctured in multiple directions, applying constant pressure (Figure 3).The needles penetrate from 1.5 to 2 mm into the dermis. As expected, the skin bleeds for a short time. The skin develops multiple microbruises in the dermis. This damage induces the release of growth factors that stimulate the production of new collagen and elastin in the upper dermis. Several studies report that 6 months after collagen-induction therapy, histology shows a dramatic increase of new collagen and elastin fibers.17-18 Aust et al showed a considerable increase in collagen and elastin