RPesidentediatric C doermatologyRneR Applications of Lasers in Medical Dermatology George Han, MD, PhD Lasers have become an important part of the Laser Treatment of Skin Diseases dermatologist’s arsenal for the treatment of skin Many common dermatoses seen in the dermatolo- diseases. As such, familiarity with the usage and gist’s office (eg, discoid lupus erythematosus [DLE], indications of this treatment modality has become morphea, alopecia) already have an established thera- important in the field of dermatology. In addition peutic ladder, with most patients responding to either to their numerous aesthetic indications, lasers first- or second-line therapies; however, a number of have proven to be efficacious in treating both pri- patients presentcopy with refractory disease that can be mary skin diseases and cutaneous malignancies. difficult to treat due to either treatment resistance or This article provides a review of the literature other contraindications to therapy. With the advent regarding laser treatment of selected skin con- and development of modern lasers, we are now able ditions to facilitate reasoned application of this to target many of these conditions and provide a via- therapeutic modality in dermatology. ble notsafe treatment option for these patients. Although Cutis. 2014;94:E20-E23. many physicians may be familiar with the use of the excimer laser in the treatment of psoriasis,1 a long- standing and well-accepted treatment modality for Dothis condition, many novel applications for different types of lasers have been developed. he use of lasers in dermatology has had a First, it is important to consider what a laser is able major impact on the treatment of many der- to accomplish to modulate the skin. With ablative Tmatologic conditions. In this column practi- lasers such as the CO2 laser, it is possible to destroy cal applications of lasers in medical dermatology superficial layers of the skin (ie, the epidermis). It will be discussed to give dermatology residents a would stand to reason that this approach would be broad overview of both establishedCUTIS indications and ideal for treating epidermal processes such as viral the reasoning behind the usage of lasers in treating warts; in fact, this modality has been used for this these skin conditions. The applications for lasers in indication for more than 3 decades, with the earliest aesthetic dermatology are numerous and are con- references coming from the podiatric and urologic stantly being refined and developed; they have been literature.2,3 Despite conflicting reports of the risk for discussed extensively in the literature. Given the human papillomavirus aerosolization and subsequent 4,5 vast variety of uses of lasers in dermatology today, a contamination of the treatment area, CO2 laser comprehensive review of this topic would likely span therapy has been advocated as a nonsurgical approach several volumes. This article will focus on recent to difficult-to-treat cases of viral warts. evidence regarding the use of lasers in medical On the other hand, the pulsed dye laser (PDL) can dermatology, specifically laser treatment of selected target blood vessels because the wavelength corre- common dermatoses and cutaneous malignancies. sponds to the absorption spectrum of hemoglobin and penetrates to the level of the dermis, while the pulse duration can be set to be shorter than the thermal From Albert Einstein College of Medicine/Montefiore relaxation time of a small cutaneous blood vessel.6 Medical Center, New York, New York. The author reports no conflict of interest. In clinical practice, the PDL has been used for the Correspondence: George Han, MD, PhD treatment of vascular lesions including hemangiomas, 7-9 ([email protected]). nevus flammeus, and other vascular proliferations. E20 CUTIS® WWW.CUTIS.COM Copyright Cutis 2014. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher. Resident Corner However, the PDL also can be used to target the ves- also the show effectiveness of both PDL and the CO2 sels in cutaneous inflammatory diseases that feature laser in treating lesions of cutaneous sarcoidosis, espe- vascular dilation and/or perivascular inflammation as cially lupus pernio.16-19 Of these 2 modalities, the use a prominent feature. of the CO2 laser for effective remodeling of lupus per- Discoid lupus erythematosus is a form of chronic nio may be more intuitive; however, it is still impor- cutaneous lupus erythematosus that may be difficult tant to note that the mechanism of action of several to treat, with recalcitrant lesions displaying contin- of these laser modalities is unclear with regard to the ued inflammation leading to chronic scarring and clinical benefit shown. Morphea and scleroderma also dyspigmentation. A small study (N12) presented have been treated with laser therapy. It is essential to the efficacy of the PDL in the treatment of DLE understand that in many cases, laser therapy may be lesions, suggesting that it has good efficacy in treat- targeted to treat the precise cutaneous manifestations ing recalcitrant lesions with significant reduction in of disease in each individual patient (eg, CO2 laser to the cutaneous lupus erythematosus disease area and treat disabling contractures and calcinosis cutis,20,21 severity index after 6 weeks of treatment and 6 weeks PDL to treat telangiectases related to morphea22). of follow-up (P.0001) with decreased erythema Again, the most critical consideration is that the and scaling.10 It is important to note, however, that treatment modality should align with the cutaneous scarring, dyspigmentation, and atrophy were not lesion being targeted. affected, which suggests that early intervention may A relatively recent development in the use of be optimal to prevent development of these sequelae. lasers has been LLLT, which refers to the use of lasers More interestingly, a more recent study expounded below levels where they would cause any thermal on this idea and attempted to examine pathophysio- effects, thereby limiting tissue damage. Although the logic mechanisms behind this observed improvement. technology has existed for decades, there has been a Evaluation of biopsy specimens before and after treat- recent flurry ofcopy reports extolling the many benefits ment and immunohistochemistry revealed that PDL of LLLT; however, the true physiologic effects of treatment of cutaneous DLE lesions led to a decrease LLLT have yet to be determined, with many studies in vascular endothelial proteins—intercellular trying to elucidate its numerous effects on various adhesion molecule 1 and vascular cell adhesion signalingnot pathways, cell proliferation, and cellular molecule 1—with a coincident reduction in the der- respiration.23-26 Upon reviewing the literature, the mal lymphocytic infiltrate in treated lesions.11 These list of cutaneous conditions that are being treated results offer a somewhat satisfying view on the cor- with LLLT is vast, spanning acne, vitiligo, wounds, relation between the theory and basic science of laserDo burns, psoriasis, and alopecia, among others.15 It is therapy and the subsequent clinical benefits afforded important to consider that the definition of LLLT by laser treatment. A case series provided further evi- in the literature is rather broad with a wide range of dence that PDL or intense pulsed light can ameliorate wavelengths, fluences, and power densities. As such, the cutaneous lesions of DLE in 16 patients in whom the specific laser settings and protocols may vary con- all other treatments had failed.12 siderably among different practitioners and therefore Several other inflammatory dermatoses can be the treatment results also may vary. Nevertheless, treated with PDL, though CUTISthe evidence for most of many studies have hinted at promising results in the these conditions is sporadic at best, consisting mostly use of LLLT in conditions that may have previously of case reports and a few case series. Granuloma faci- been extremely difficult to treat (eg, alopecia). Earlier ale is one such condition, with evidence of efficacy of trials had demonstrated a faster resolution time in the PDL dating back as far as 1999,13 though a more patients with alopecia areata when LLLT was added recent case series of 4 patients only showed response to a topical regimen27; however, the improvement in 2 patients.14 Because granuloma faciale features was modest and lesions tended to improve with or vasculitis as a prominent feature in its pathology, without LLLT. Perhaps more compelling is the use of targeting the blood vessels may be helpful, but it is LLLT in treating androgenetic alopecia, a condition important to remember that there is a complex inter- for which a satisfying facile treatment would truly play between multiple factors. For example, treat- carry great impact. Although physicians should be ment with typical fluences used in dermatology can cautious of studies regarding LLLT and hair regrowth be proinflammatory, leading to tissue damage, necro- that are conducted by groups who may stand to sis, and posttreatment erythema. However, low-level benefit from producing such a device, the results are laser therapy (LLLT) has been shown to downregulate nonetheless notable, if only for the relative paucity proinflammatory mediators.15 Additionally, the pres- of other therapeutic approaches toward this condi- ence of a large burden of inflammatory cells also may tion.28,29 A randomized, double-blind,