An evidence-based, peer-reviewed journal for practicing clinicians in the field of dermatology
Issue link: https://jcadonline.epubxp.com/i/934167
23 JCAD JOURNAL OF CLINICAL AND AESTHETIC DERMATOLOGY February 2018 • Volume 11 • Number 2 R E V I E W two, four, and six weeks, and three and six months post-resurfacing. The retrospective group included the same number of age- and treatment-matched subjects who did not receive LED therapy and were evaluated three and six months post- resurfacing. Healing response was rated as Very Good (85–100% improvement), Good (65–84% improvement), Fair (45–64% improvement), Poor (<45% improvement), or Bad (little improvement or worsened). Overall, mean efficacy results were similar across treatment groups (Table 3). No subjects were rated as Poor or Bad. At the three-month assessment, the overall efficacy of the prospective-treated group (Very Good + Good) was significantly better than both the prospective- control and retrospective groups (p<0.01). At the six-month assessment, the prospective-treated group showed slightly better improvement than the other two groups, but the difference was not significant. The symptoms of exudation, crusting, pain, and edema resolved approximately 50 percent faster in the prospective-treated group (p<0.001) as did erythema (p<0.0001). At six months, there was no significant difference in wrinkle improvement between the prospective- treated and untreated side, but the skin appeared younger-looking on the LED-treated side. These results have been confirmed in several subsequent studies. 13,15–17 Psoriasis. In the Unites States, the incidence of psoriasis in adults has been increasing from 50.8/100,000 during the 1970s to 100.5/100,000 during the 1990s. 18 As increasing attention was being paid to visible red (633nm) and near infrared (830nm) light-emitting diodes for treating various dermatological conditions, the following pilot study was designed to assess the efficacy of combining 830nm and 633nm LED phototherapy for treating recalcitrant psoriasis. 19 Informed and consenting subjects with psoriasis (N=9) with a mean age of 34.3 years and Fitzpatrick Skin Types I to IV were enrolled. All had chronic plaque psoriasis (n=8) and guttate psoriasis (n=1) of up to 35 years duration and affecting 15 to 80 percent of their body surface area. Most had become resistant to conventional treatments. Each subject was treated sequentially with LED arrays delivering continuous-wave 830nm, 60J/ cm 2 and 633nm, 126J/cm 2 during two weekly 20-minute sessions for 4 to 5 weeks with two days between sessions. Specified psoriatic plaques or guttate papules were chosen to be treated. All subjects completed their LED regimens with five subjects requiring a second treatment regimen. Among evaluable subjects (n=7) at three- to four-month follow-up evaluations, clearance rates ranged from 60 to 100 percent of specified treatment sites. Overall patient satisfaction was very high. Protoporphyrin present in psoriatic skin apparently acts as a photosensitizer. A subsequent study further demonstrated the beneficial effects of phototherapy for treating psoriasis. 20 Photodynamic therapy (PDT): phototherapy combined with 5-aminolevulinic acid. PDT involves administration of a light-sensitive substance, or photosensitizer, followed by exposure to the wavelength of light that corresponds to the absorbance band of the sensitizer. Both red and blue LED, as well as intense pulsed light technology, have been used to activate the photosensitizer. Cytotoxic free radicals form in the presence of oxygen which causes cell death. 21 The most common photosensitizer is 5-aminolevulinic acid (ALA). Photodynamic therapy with ALA has been used to treat a range of conditions, including from pre-cancerous and cancerous lesions 22,23 and photoaged skin. 24,25 Squamous cell carcinoma in situ (Bowen's disease). The safety and efficacy of PDT was compared with cryotherapy for treating Bowen's disease. 26 Lesions were randomized to undergo cryotherapy with liquid nitrogen (n=20) or PDT (n=20) using ALA as the photosensitizer. ALA was applied topically four hours prior to irradiation (125J/cm 2 ; 70 mW/cm 2 ). Subjects were evaluated every two months and retreated as needed. TABLE 2. Patient characteristics and days to healing PATIENT SEX AGE DAYS TO HEALING SKIN TYPE TREATED UNTREATED 1 M 58 14 27 III 2 F 46 13 27 III 3 F 49 15 29 IV 4 F 57 12 26 IV 5 F 55 14 28 III 6 F 48 13 25 II 7 F 50 14 27 III 8 F 58 15 29 II 9 M 59 13 25 III 10 F 44 12 25 IV Mean (SD) -- 52.4 (5.6) 13.5 (0.34) 26.8 (0.49) a -- a Significant between-group difference (p<0.0001). From Trelles et al 2006 13 FIGURE 2. The effectiveness of phototherapy for the treatment of rosacea is clearly demonstrated in this patient before (left) and three months after nine weekly treatment sessions with a red light emitting diode (right). Images courtesy of the author.