'", Laser Treatment of Hypertrophic Scars, Keloids, and Striae Tina S. Alster, MD, and Christiane Handrick, MD The successful use of the 585-nm pulsed dye laser leading to decreased scar erythema, 585-nm for the treatment of hypertrophic scars has been pulsed dye laser irradiation has been shown to well established over the past decade. Although 5 favorably affect scar pliability, hypertrophy, and years ago this treatment option might have been 26 considered as a viable choice only affer all other symptoms of patient discomfort. ,28,32 Following methods failed, it is now generally recognized as an initial observation of pulsed dye laser improve- an excellent first-line treatment option. Early scar ment of argon laser-induced scars, Alster and col- treatment with pulsed dye laser irradiation effec- leagues26-28,32 have reported similar improve- tively prevents scar formation or worsening and ments in surgical, traumatic, acne, and burn scars. yields a better and more prolonged clinical im- Subsequent publications by Goldman and Fitz- provement. The concomitant use of corti coste- roids, 5-fluorouracil, or other treatments is proving patrick29,33 have corroborated these findings. Re- to be of particular importance in reducing scar search by McCraw and colleagues>' promoted bulk and SYmptoms of more proliferative scars. early postoperative initiation of pulsed dye laser Although optimal management for keloids and treatment in order to prevent scar formation or striae has yeT to be determined, pulsed dye laseR worsening in scar-prone individuals and body iRRadiation will no doubt continue to playa role in their treatment. locations. Reiken and his colleagues= then defin- Copyright © 2000 by W.B. Saunders Company itively determined the superiority of the 585-nnm wavelength in reducing hypertrophic scar growth (Fig 1). Similarly, the 585-nm pulsed dye laser UTANEOUS DERMAL INJURY eventuates has proved useful in the treatment of striae disten- in the inevitable formation of a scar, which C sae (Fig 2).36 Factors determining patient selec- may be cosmetically acceptable or unacceptable. tion, choice oflaser parameters, specific treatment The reparative process involves inflammation, protocols, and management of possible adverse granulation tissue formation, and matrix remod- effects to optimize laser treatment of hypertrophic eling resulting in a variable degree.of fibrosis. 1,2 In scars, keloids, and striae are reviewed in this some cases, exuberant fibrosis may produce dis- article. figuring hypertrophic scars or keloids. In contrast, endogenous factors, including mechanical skin CHARACTERISTICS OF HYPERTROPHIC stretching and hormonal influences, may lead to SCARS, KELOIDS AND STRIAE dermal dehiscence resulting in striae distensae or "stretch marks." Hypertrophic scars appear clinically as erythem- Hypertrophic scars, keloids, and striae have atous, raised, firm areas of fibrotic skin typically limited to the site of the original wound or trauma. been notoriously difficult to eradicate with tradi- They usually form within the first month after the tional treatments, including surgical excision, inciting cutaneous injury, often becoming flatter corticosteroids, and continuous wave laser de- and more pliable over time. struction, yielding either unsatisfactory results or Keloids are even firmer, reddish-purple nodules high lesional recurrence rates3-25 Over the past that extend in a claw-like manner beyond the con- decade, advances in pulsed laser technology have fines of the original (sometimes only slight) enabled successful treatment of these lesions, giv- ing millions of patients a new therapeutic option. The experimental use of the 585-nm pulsed dye From the Washington Institute of Derma tologic Laser Surgery, laser for hypertrophic scars within port-wine Washington, DC. stains in the late 1980s initiated a cascade of stud- Address reprint requests to Tina S. Alster, MD, 2311 M Street, NW, Suite 200, Washington, DC 20037. ies with this vascular-specific laser to improve the Copyright © 2000 by W.B. Saunders Company 26 32 textural quality and appearance of scars. - In 1085-562910011904-0009$10.0010 addition to destruction of its microvascular target, doi:10.1 053Isder.2000.18369 Seminars in Cutaneous Medicine and SurgeRY, Vol 19, No 4 (December), 2000: pp 287-292 287 , I 288 ALSTERAND HANDRICK Fig 1. HyperTrophic laceration scars on the cheek (A) before and (B) 2 months after second pulsed-clye laser treatment with average fluence of 5.0 J/cm2 (lD-mm spot). wound. Their development starts weeks to years sion); intentional surgical procedure (eg, exci- after trauma (although they can arise spontane- sion, electrocautery, cryotherapy, laser surgery); ously) and may continue to worsen for decades in or of vaccination or cystic acne. Their prevalence e~treme cases. ranges from 4.5% to 16% of the population.F Sites Both hypertrophic scars and keloids tend to be of predilection include slow-healing areas (eg, an- pruritic or painful on palpation and can be cos- terior chest) and movement- and pressure-depen- metically unsightly. They may be a consequence dent regions (eg, scapula, shoulders, ear lobes). of traumatic injury (eg, laceration, burn, abra- They occur more often in individuals with darker Fig 2. Striae (A) before and (B) 6 weeks after second 585·nm pulsed-clye laser treatment at average fluence of 3.0 J/cm2 (10·mm spot). ;'1 HYPERTROPHIC SCARS, KELOIDS, AND STRIAE 289 skin tones and patients with impaired collagen examination of scars after laser irradiation reveals synthesis (eg, Ehlers-Danlos syndrome). Other improvement in dermal collagen with finer, more contributing factors to the development of hyper- fibrillar, and looser arrangement of collagen fi- trophic scars and keloids include surgery per- bers.28,32 The pulsed dye laser induces selective formed during pubertal growth spurts, post-trau- vascular thermal injury, leading to thrombosis, matic traction and tension, secondary infection, vasculitis, and gradual local repair with neovascu- and foreign body irritation (eg, granulomatous re- larization.w+" Irradiated scars have also been sponse to suture material). Scar formation is a shown to exhibit a large number of regional mast complex multistep process that is not yet fully cells, which may elaborate a number of cytokines understood, so no single cell type or factor can be that could potentially stimulate the process of col- made responsible for the excessive fibrosis ob- lagen remodeling.w>? It is also possible that col- served. The histopathologic appearance of hyper- lagen synthesis can be stimulated by dermal heat trophic scars is characterized by whorls of young conduction from the laser-irradiated blood ves- fibrous tissue and fibroblasts in a haphazard ar- sels. An additional mechanism of laser action may rangement. Keloids additionally display thick, eo- include selected microvascular destruction pro- sinophilic, acellular bands of collagen on micro- ducing local tissue ischemia and the release of scopic examination." The microvessels in both collagenase, leading to collagenolysis.>? lesions are often occluded by an excess of endo- thelial cells.v' Although keloids produce high lev- LASER TREATMENT PROTOCOL els of hyaluronidase, low concentrations of colla- Patient Selection genase are typical for hypertrophic scars.>? 5triae are linear bands of atrophic and wrinkled Individuals with lighter skin tones (phototypes skin which occur after excessive dermal stretch- I and II) are the best treatment candidates because ing andJor under the influence of estrogens and little epidermal melanin is present to serve as a corticosteroids.w+t They become manifest after competing chromophore for pulsed dye laser ab- pubertal growth spurts, pregnancy, rapid weight sorption. Patients with darker skin types can un- gain, and long-term internal or external cortico- dergo pulsed dye laser treatment as well, but flu- steroid use. In rare cases, they may also occur after ences typically need to be lowered and patients infections with typhus, para typhus, influenza, or warned of the possibility of postoperative dyspig- tuberculosis. They often exhibit scar-like features, mentation. All body areas affected by keloids and with early striae appearing erythematous and late scars appear to be amenable to pulsed dye laser striae showing hypopigmentation and fibrosis. treatment. A history carefully obtained before Striae are caused by connective tissue alteration treatment is important because the mechanism of following elastolysis with initial mast cell degran- the injury, scar duration, and prior treatment at- ulation and macrophage degradation. Histologi- tempts may influence treatment parameters. Pre- cally, they are characterized by the presence of vious electrocauterization, cryotherapy, and sur- dysmorphic elastic fibers and reduced collagen gical excision typically produce increased tissue fibers in the dermis.t> The prophylactic or thera- fibrosis, necessitating the use of higher fluences peutic use of topical agents, such as retinoic acid, andJor a greater number of laser sessions.t? Pa- has shown limited ability to change the structure tients who are on anticoagulant or antiplatelet and appearance of these lesions+t-t> medications (eg, coumadin, aspirin) should dis- continue their use before laser treatment in order LASER-INDUCED EFFECTS ON to reduce the intensity and duration of postoper- HYPERTROPHIC SCARS, KELOIDS, ative purpura. Preoperative and follow-up photos AND STRIAE are an effective way to document and control