***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Acne scarring is a consequence of abnormal resolution of wound healing after damage that occurs in the sebaceous follicle during acne inflammation . No trial to date has evaluated the efficacy of the combination of microdermabrasion and photodynamic therapy for acne scarring . This single-center , double-blinded pilot study enrolled subjects with moderate-to-severe acne scarring who were r and omly assigned in a blinded fashion to use aminolevulinic acid and vehicle in a split-face fashion after full-face treatment with microdermabrasion .  On average , 80 percent of the patients displayed more improvement in scarring on the aminolevulinic acid split face versus the vehicle split face after five treatments . Using two different noninvasive mechanisms of targeting acne scarring provided for a safe treatment regimen characterized by more efficacious results with respect to higher rates of scarring improvement BACKGROUND Acne patients who fail to respond to conventional treatments have been treated with isotretinoin , an effective treatment coming under strict regulation due to the risk of significant side effects . Photodynamic therapy ( PDT ) may be a viable alternative treatment for recalcitrant acne of various types and levels of severity . OBJECTIVE To determine the safety and efficacy of combination PDT with topical 5-aminolevulinic acid ( ALA ) and activation by long-pulsed , pulsed dye laser ( LP PDL , 595 nm ) energy with topical therapy in patients with mild to severe acne . METHODS A prospect i ve , controlled pilot , proof-of-principle study of 19 consecutive patients ( aged 16 - 47 years , Fitzpatrick skin types I-VI ) with mild to severe cystic , inflammatory , or comedonal acne of the face was conducted . All patients had failed conventional therapy , including oral antibiotics , topical treatments , hormonal therapy , laser procedures ( without ALA ) , and /or oral isotretinoin . Fifteen patients were treated with ALA PDT and 4 patients served as controls ; all were continued on topical medications . Patients undergoing PDT were initially r and omized to receive either blue light or laser energy . Because recrudescence occurred in 1 patient while undergoing multiple treatments with ALA and blue light , all subsequent patients were treated with ALA and laser energy . The total number of patients treated with LP PDL-mediated ALA PDT was 14 . ALA was applied for a short 45-minute incubation followed by 1 minimally overlapping pass with the LP PDL ( 595 nm , 7.0 - 7.5 J/cm2 fluence , 10-ms pulse duration , 10-mm spot size , and dynamic cooling spray of 30 ms with a 30-ms delay ) . Patients treated with conventional therapy ( oral antibiotics , oral contraceptives , and topical medications ) or laser energy without ALA PDT served as control groups . Patients were followed monthly for up to 13 months . RESULTS Complete clearance was achieved in 100 % ( 14 out of 14 ) patients in the LP PDL PDT-treated group . A mean of 2.9 treatments ( range 1 - 6 ; 2.0 - 3.7 , 95 % CI ; n=14 ) was required to achieve complete clearance for a mean follow-up time of 6.4 months ( range 1 - 13 ; 3.8 - 8.9 95 % CI ; n=14 ) . The patient mean percent lesional clearance rate per treatment was 77 % ( 64%-90 % , 95 % CI ; n=14 ) . Improvement in acne lesions became apparent within 1 to 2 weeks after the first treatment . Clearance in the LP PDL PDT group was superior to control groups . In the LP PDL-only control group ( n=2 ) , the patient mean percent lesional clearance rate per treatment was 32 % without complete clearance after 3 to 4 treatments . In the oral antibiotics , oral contraceptives , and topicals control group ( n=2 ) , the clearance rate per treatment was 20 % , the mean clearance rate per month was 4 % , and complete clearance was not achieved after 6 to 10 months . In the LP PDL-mediated PDT group , treatments were well-tolerated with minimal erythema lasting 1 to 2 days . No cases of crusting , blistering , purpura , scarring , or dyspigmentation occurred . A reduction in the erythema in erythematous acne scars was observed . CONCLUSION For teenage to adult patients with recalcitrant comedonal , inflammatory , or cystic acne of various degrees of severity , ALA PDT with activation by LP PDL appears to be a safe and effective treatment with minimal side effects . LP PDL-mediated PDT may serve as an important alternative to isotretinoin . Cosmetically well-accepted , LP PDL PDT combined with topical therapy is the first PDT modality to achieve complete clearance with long-term follow-up as compared to controls BACKGROUND Long-pulsed dye laser (LPDL)-assisted photodynamic therapy has been suggested to be superior to laser alone for acne vulgaris but no evidence is available . OBJECTIVE To evaluate the efficacy and safety of LPDL alone versus LPDL in photodynamic therapy with methylaminolevulinic acid ( MAL-LPDL ) for acne vulgaris . METHODS Fifteen patients received a series of 3 full-face LPDL treatments and half-face prelaser MAL treatments ; the latter being r and omly assigned to the left or right side . RESULTS Inflammatory lesions were reduced more on MAL-LPDL-treated than on LPDL-treated sides ( week 4 : 70 % vs 50 % , P = .003 ; week 12 : 80 % vs 67 % , P = .004 ) . Noninflammatory lesions reduced similarly . Patient satisfaction was slightly greater with MAL-LPDL versus LPDL treatments ( scale 0 - 10 : week 4 : 7 vs 6 , P = .034 ; week 12 : 8 vs 7.5 , P = .034 ) . Fluorescence measurements detected photobleaching with MAL-LPDL ( 35.3 % ) and LPDL ( 7.3 % ) treatments ( P < .001 ) . Erythema , edema , and pustular eruptions intensified from MAL incubation . No patients experienced pigment changes or scarring . LIMITATIONS The sample size was limited . The split-face design in this r and omized controlled trial does not allow us to draw conclusions about the efficacy of the LPDL , only about the efficacy of MAL-LPDL compared with LPDL alone . CONCLUSIONS MAL-LPDL is slightly superior to LPDL for the treatment of inflammatory acne BACKGROUND The success rates of conventional treatments to acne vulgaris are limited because of intolerance and resistance . Photodynamic therapy with topical 5-aminolevulinic acid ( ALA ) and red light has been introduced . However , the side effects especially pigmentation are common . OBJECTIVE To study the efficacy and safety of ALA-photodynamic therapy ( PDT ) with 420 - 950 nm intense pulsed light ( IPL ) in Chinese patients with acne vulgaris . METHODS Forty-one patients with moderate to severe facial acne were r and omly assigned to ALA-IPL-PDT group and IPL group . Ten percent topical ALA was applied to patients in the ALA-IPL-PDT group , while placebos were applied to patients in the IPL group . After 1 h occlusion , all patients were illuminated with 420 - 950 nm IPL . The patients in both groups had four treatment sessions with 1-week intervals . One week after each treatment and 4 , 8 , and 12 weeks after four sessions , acne lesion counts and adverse events were observed . RESULTS Twelve weeks after treatments , mean reductions of global lesion counts of ALA-IPL-PDT group and IPL group were 75.2 % and 51.0 % , respectively . Mean reductions of inflammatory and non-inflammatory lesion counts  in ALA-IPL-PDT group were ( 83.6 ± 4.1)% and ( 57.5 ± 6.8)% , respectively . No severe adverse events were observed . CONCLUSION ALA-IPL-PDT is an effective treatment for moderate to severe acne vulgaris , and side effects are mild and reversible BACKGROUND Photodynamic therapy ( PDT ) has been proposed as a treatment option for acne vulgaris . The authors have proposed in this work a liposomal delivery for methylene blue ( MB ) for selective acne treatment . OBJECTIVES To evaluate the efficacy and tolerability of liposomes loaded methylene blue ( LMB ) based photodynamic therapy in patients with mild-to-moderate acne vulgaris in a r and omized , controlled and investigator blinded study . MATERIAL S AND METHODS Liposomes loaded methylene blue ( LMB ) was prepared and studied for different pharmaceutical properties and formulated in hydrogel ( MB 0.1 % ) . Permeability and selective sebaceous gl and targeting in mice skin was studied . Gel containing LMB was used for treating 13 patients complaining of mild-moderate acne vulgaris once a week for two weeks . Efficacy evaluation included changes in lesions counts , clinical assessment s of clinical improvement by patients and evaluating dermatologists . Pain and local adverse effects were also evaluated . RESULTS The mechanism of the drug released from liposomes ( both in pH = 5.5 and in pH = 7.2 ) was following zero order kinetics with significant increase in the drug released in pH = 5.5 . Drug released from free methylene blue ( FMB ) gel was significantly higher ( P < 0.05 ) with Higuichi 's diffusion model than LMB gel , which followed zero order kinetics . Free MB gel showed superficial destruction in the mice hair shaft while LMB showed complete destruction of pilosebaceous unit . After only two sessions , there was a 83.3 % reduction in the number of inflammatory acne lesions and a 63.6 % reduction in the number of non-inflammatory acne lesions . At 12 weeks , 90 % of patients had a moderate-to-marked improvement of their acne in the treated areas . Most patients had no pain ; also no serious adverse side effects were recorded . All the patients had no edema . Slight transient hyperpigmentation was seen only in three patients . CONCLUSION Liposomal MB hydrogel selectively delivered MB to sebaceous gl and and was effective in photodynamic treatment of mild-to-moderate acne vulgaris BACKGROUND There remains the need for more effective therapeutic options to treat acne vulgaris . Interest in light-based acne treatments has increased , but few r and omized , controlled clinical trials assessing the value of photodynamic therapy ( PDT ) for acne have been reported . AIMS We sought to examine the efficacy of PDT using 5-aminolevulinic acid ( ALA ) and pulsed dye laser therapy in the treatment of acne . PATIENTS / METHODS We conducted a r and omized , controlled , split-face , single-blind clinical trial of 44 patients with facial acne . Patients were r and omized to receive three pulsed dye laser treatments to one side of the face after a 60 - 90 min ALA application time , while the contralateral side remained untreated and served as a control . Serial blinded lesion counts and global acne severity ratings were performed . RESULTS Global acne severity ratings improved bilaterally with the improvement noted to be statistically significantly greater in treated skin than in untreated skin . Erythematous macules ( remnants of previously active inflammatory lesions ) decreased in number in treated skin when compared with control skin and there was a transient but significant decrease in inflammatory papules in treated skin when compared with untreated skin . There were no other statistically significant differences between treated and untreated sides of the face in terms of counts of any subtype of acne lesion . Thirty percent of patients were deemed responders to this treatment with respect to improvement in their inflammatory lesion counts , while only 7 % of patients responded in terms of noninflammatory lesion counts . CONCLUSIONS PDT with the treatment regimen employed here may be beneficial for a subgroup of patients with inflammatory acne Recent advances in light therapy coupled with photosensitizers offer alternatives to topical creams and gels and systemic oral agents for acne treatment . To examine the safety and efficacy of the photosensitizer 5-aminolevulinic acid ( ALA ) in patients with moderate-to-severe acne , a r and omized , split-face study , using ALA on one side of the face , was followed by exposure of the entire face to 532 nm potassium titanyl phosphate ( KTP ) laser .  Eight patients completed three treatments for up to 12 weeks . The average acne grading at baseline was 3.20 , and improved to 2.12 at 12 weeks ( 34 % improvement ) . Use of ALA  improved acne by 52 % compared with 32 % on the side that did not receive the photosensitizer . Further studies are warranted to establish optimal parameters for photosensitizer use combined with light therapy for treatment of moderate-to-severe acne ; however , the combined use of ALA and a 532 nm laser suggests promising results for acne treatment BACKGROUND AND OBJECTIVES The reaction to intense pulsed light ( IPL ) on Asian skin often differs from that on Caucasian skin . The study reported herein evaluated the effect on acne vulgaris of IPL alone and when IPL was combined with photodynamic therapy ( PDT 
    Output:
    
Results The most common photosensitizers used were 5-aminolevulinic acid and methyl aminolevulinate , and both showed similar response .
Red light was the most frequently used light source , followed by intense pulsed light , and showed comparable results .
Inflammatory and non-inflammatory lesions both responded to treatment , with inflammatory lesions showing greater clearance in most studies .
Adverse events associated with PDT for acne were mild and included pain on illumination and post-procedural erythema and edema .
PDT has been safely used in higher Fitzpatrick skin types ( III – IV ) , although these patients had a higher risk of transient hyperpigmentation .
Conclusion This review supports PDT as an efficacious treatment for acne and a good adjunctive treatment for mild to severe acne , especially in patients who have not responded to topical therapy and oral antibacterials , and are not great c and i date s for isotretinoin .