Keloids and hypertrophic scars are quite common diseases that can occur after any kind of wound and skin inflammation in predisposed individuals. Despite their benign nature, they can be aesthetically disabling and they are often accompanied by unpleasant symptoms such pain, burning and itching. Several approaches have been tried but most of them with poor results. Ablative fractional CO(2) laser seems to be an encouraging approach in treatment of keloids and hypertrophic scars, not only for its efficacy, but also for its low harmfulness. Radiotherapy following surgical excision is commonly used to treat these scars, but an increased incidence of different kinds of cancer from radiation has been demonstrated in several cases. Compared to radiotherapy, the use of CO(2) laser after surgical excision of keloids has shown great results with no recurrence and without the risk of carcinogenesis.

Keloids and hypertrophic scars are both abnormal wound responses in predisposed individuals but they differ in that keloids extend beyond the original wound and almost never regress, while hypertrophic scars remain within the original wound and tend to regress. How keloids grow is not totally clear because there is no animal model; in fact, keloids affect only humans. Different injuries can result in keloids, including burns, surgery, ear piercing, lacerations, abrasions, tattooing, vaccinations, injections, insect bites and any process causing skin inflammation (chicken pox, acne, folliculitis, zoster). Skin or wound tension is considered a critical factor in the formation of keloids and hypertrophic scars. This study is based on eight consecutive patients (four females and four males, F:M = 1:1) with a total of 12 keloids. All of whom were treated monthly with a MiXto SX CO(2) laser, using 13 W of power, 8 SX of index and 40% coverage (density) in combination with Same Plast Gel(®) twice a day. Each scar required 12 treatments, and all the patients, followed up for 1 year after the last treatment, had optimum results and no recurrence.

Background CO 2 laser resurfacing is a powerful tool for the treatment of several skin conditions such as fine and coarse wrinkles, scars of various origin, uneven pigmentation, dilated pores et al. Some major drawbacks have progressively limited its use: the need for effective anaesthesia, the downtime, the risk of dyspigmentation and scarring, the need for intensive postoperative care, the long-lasting erythema and the long avoidance of sun exposure. Fractional photothermolysis was introduced by Huzaira and colleagues in 2003. It was developed to overcome the above-mentioned drawbacks in the treatment of photo damaged skin. Fractional Laser Resurfacing with the midinfrared lasers uses an invisible laser beam which is strongly absorbed by water, in order to reverse the effects of skin aging and scarring. Near infrared wavelengths (Fraxel, Reliant, 1550nm; Lux 1540, Palomar) cause significant pain and require some form of anaesthesia. This is a time consuming and costly aspect. Another disadvantage for the operator is that most of these devices are only capable of performing this kind of treatment. The use of ablative lasers in a fractional mode was introduced in 2006. The lesser depth of immediate tissue necrosis, in comparison to the midinfrared wavelengths, together with the possibility of further heat deposition in the dermis, significantly reduces the pain caused by the procedure, without decreasing its efficacy. A new CO2 laser (Active FX, Lumenis, 10600nm) with less penetration was shown to be more tolerable, but the 1.3 mm spot still makes some local anaesthesia and\or cooling necessary. The spot distribution is not distributed as uniformly as with the midinfrared devices. A more recent CO 2 laser system (Slim Evolution, Lasering,) with a microspot system (300µ) fractional modality (Mixto SX) has been developed with a new scanning algorithm that keeps the longest possible interval between two adjacent spots, in order to minimize the heat accumulation around the treated areas. This is supposed to significantly reduce the pain during the procedure. An overview of the characteristics of several fractional devices is shown in table number 1.

The combined use of silicone gel sheeting and a 532-nm millisecond laser is an effective and safe treatment for hypertrophic scars and keloids.