cochrane database of systematic reviews (protocols) || light therapies for acne

Light therapies for acne (Protocol)

Car J, Car M, Hamilton F, Layton A, Lyons C, Majeed A

This is a reprint of a Cochrane protocol, prepared and maintained by The Cochrane Collaboration and published in The CochraneLibrary 2009, Issue 3

http://www.thecochranelibrary.com

Light therapies for acne (Protocol)

Copyright © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

http://www.thecochranelibrary.com

T A B L E O F C O N T E N T S

1HEADER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8CONTRIBUTIONS OF AUTHORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8DECLARATIONS OF INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9SOURCES OF SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iLight therapies for acne (Protocol)


[Intervention Protocol]

Light therapies for acne

Josip Car1, Mate Car1, Fiona Hamilton1, Alison Layton2 , Colin Lyons3, Azeem Majeed1

1Department of Primary Care and Social Medicine, Faculty of Medicine, Imperial College London, London, UK. 2Harrogate Health

Care NHS Trust, Harrogate District Hospital, Harrogate, UK. 3Department of Primary Care & Social Medicine, Faculty of Medicine,

Imperial College London, London, UK

Contact address: Josip Car, Department of Primary Care and Social Medicine, Faculty of Medicine, Imperial College London, Reynolds

Building, St Dunstan’s Road, London, W6 8RP, UK. [email protected].

Editorial group: Cochrane Skin Group.

Publication status and date: New, published in Issue 3, 2009.

Citation: Car J, Car M, Hamilton F, Layton A, Lyons C, Majeed A. Light therapies for acne. Cochrane Database of Systematic Reviews2009, Issue 3. Art. No.: CD007917. DOI: 10.1002/14651858.CD007917.


A B S T R A C T

This is the protocol for a review and there is no abstract. The objectives are as follows:

To explore the effects of light treatment of different wavelengths for acne.

1Light therapies for acne (Protocol)


mailto:[email protected]

B A C K G R O U N D

Description of the condition

Acne is a common skin condition which tends to affect the face,

chest, and back. It can range from a mild form with comedones

(blackheads and whiteheads) and a few small spots (pustules and

papules) to more severe forms with many lesions, including nod-

ules and deep cysts. Mild acne is more prevalent than the severe

form (Stathakis 1997; Kilkenny 1998) and most teenagers will

grow out of it. However, it can persist into adulthood, or start in

adulthood, when it is often more difficult to manage and tends to

affect women more often than men (Goulden 1999; Poli 2001;

Goulden 2003).

Impact

Acne affects 70% to 90% of teenagers (Leyden 1997; Webster

2002), and can lead to scarring of the skin, which is difficult

to treat effectively (Layton 1994; Jordan 2000). Sufferers often

develop low self-esteem, and low mood (Baldwin 2002; Tan 2004;

Thomas 2004), which can even lead to problems with employment

(Cunliffe 1986). The impact of acne has been assessed to be as

severe as epilepsy or asthma on the quality of life (Thomas 2004).

Causes

Acne is usually precipitated in puberty by a rise in hormones, par-

ticularly androgens (Thiboutot 2004, Zouboulis 2004). This leads

to enlargement and hyperkeratinisation of the sebaceous glands of

the pilo-sebaceous unit. Sebum builds up, plugging the hair fol-

licle and leading to the formation of comedones (whiteheads and

blackheads, Cunliffe 2004). Finally, skin bacteria, notably Propi-onibacterium acnes (P. acnes), become trapped inside the duct and

induce an intense inflammatory response, resulting in pustules,

papules and, in the worse cases, nodules and cysts. Insulin resis-

tance has been implicated in the development of acne, as acne is a

common complaint of women with polycystic ovarian syndrome

(Archer 2004; Pfeifer 2005).

Conventional treatments

First line treatments for acne include topical agents, such as

retinoids and benzoyl peroxide, to target sebum production and

plugging of the hair follicle (Garner 2003). Topical and oral an-

tibiotics may also be prescribed to control the acne bacteria, al-

though antibiotic resistance is becoming a problem (Seaton 2003).

Women may be prescribed oral contraception containing cypro-

terone-acetate (Dianette), which is antiandrogenic (Arowojolu

2004). Oral isotretinoin is very effective for moderate to severe

acne. It is a synthetic form of vitamin A. It is often curative but

has side-effects (Greenwood 1986) which some with the condition

find unacceptable. Common side-effects include dry skin, eyes,

lips, and mucous membranes (Charakida 2004). It is also terato-

genic, limiting its use in women of childbearing age (Stern 1989).

The incidence of side-effects of treatment with Isotretinoin and

its efficacy, is the subject of an ongoing Cochrane review (Gupta

2004).

Description of the intervention

Light therapies for acne utilise light with different properties

(wavelength, intensity, coherent/incoherent light) to achieve a ben-

eficial result for those with acne (Mariwalla 2005). Lasers are the

commonest light sources for acne therapy. ’Laser’ stands for ’light

amplification by stimulated emission of radiation’. They produce

a high-energy beam of light of a precise wavelength range, which

can be focused accurately. Several different delivery systems are

used in clinical practice, incorporating timing controls for safety

and cooling systems to reduce discomfort during treatment.

How the intervention might work

Light therapies for acne are believed to work mostly by killing

P. acnes and by damaging and shrinking sebaceous glands thus

reducing sebum output. Studies report few side-effects (Elman

2003) and these are temporary (Friedman 2004). Light therapies

may be given once or twice weekly as a course of 6 to 10 treatments,

and each irradiation lasts 10 to 20 minutes (Mariwalla 2005).

Treatment is not usually available in the NHS and may be accessed

privately via dermatologists or clinics, but can be expensive.

P. acnes produce endogenous porphyrins, which absorb light to

form highly reactive singlet oxygen, which destroys the bacteria

(Mariwalla 2005). Porphyrins have peak absorption at blue light

wavelengths, so blue light is often used to treat acne. Red light is

also absorbed by porphyrins, and can penetrate deeper into the skin

(Ross 2005) where it may directly affect inflammatory mediators.

Other light therapies attempt to selectively target and damage se-

baceous glands directly, reducing their size and thus sebum output

(Lloyd 2002). These include infra-red lasers, low energy pulsed-

dye lasers, and radiofrequency devices (Mariwalla 2005).

Photodynamic therapy (PDT) uses specific light-activating

creams. These are absorbed into the skin and amplify the response

to light therapy but tend to produce more severe side-effects. There

are also concerns that PDT may interfere with the skin’s natural

immune mechanisms (Böhm 1998) and so cause long-term skin

damage.

Some authors have observed an increase in transforming growth

factor (TGF)-Beta1 mRNA 24 hours after treatment with lasers.

TGF-Beta1 is an immunosuppressive cytokine that also stimulates

the formation of collagen. It is thought that its increase following

laser treatment promotes the resolution of inflammation (Seaton

2006).

Why it is important to do this review

Acne is chronic, often flares up for no obvious reason, and increas-

ingly persists well into adulthood. Most oral and topical treatments

are less effective than oral isotretinoin, and combination treatment

regimens can be problematic, time consuming, and difficult to

follow. Antibiotics are often used, but there are concerns that this



may give rise to bacterial resistance (Crawford 1979; Leyden 1983;

Eady 1998). Thus all conventional treatments have limitations.

Recently some authors have proposed diverse light therapies as a

new treatment, although the outcomes of existing trials are con-

tradictory. Light therapies also seem to be increasingly popular

among consumers and many light sources are now offered for peo-

ple to purchase directly using the Internet. Therefore there is a

lot of public interest in this treatment, as well as interest from

health service commissioners. Establishing what evidence there is

to support treatment of acne with light of different wavelengths is

therefore critical (Mariwalla 2005).

O B J E C T I V E S

To explore the effects of light treatment of different wavelengths

for acne.

M E T H O D S

Criteria for considering studies for this review

Types of studies

Randomised controlled trials (RCTs), which may be of two types:

those which compare two groups of subjects where one group is

randomised to receive treatment and the other serves as the control

group; and those which apply treatment randomly to one part of a

subject’s body compared with another part which serves as control

(such as split-face studies). We will not include cross-over trials

because an intervention for acne may have a lasting effect that can

carry over to subsequent periods of the trial.

Types of participants

Anyone with a diagnosis of mild, moderate, or severe acne vulgaris

defined by any classification system.

Types of interventions

We will search for any therapy based on the healing properties of

light for treatment of acne vulgaris. Therapies that combine light

with other treatment to boost the effect of light will also be ac-

cepted. We will focus on a comparison between the effectiveness

of treatment with light of different properties - coherence, wave-

length, and intensity.

A study will be included if the description of the intervention

that was applied was adequately described (described in sufficient

detail to understand the key steps undertaken) and used a validated

measure of improvement in acne vulgaris as one of its outcomes.

When necessary, we will request additional information describing

the intervention from study authors to help determine eligibility

(for example, details of the measurement methods used).

Types of outcome measures

Primary outcome measure

(i) Participant’s global assessment of improvementThis is likely to be recorded using a Likert or Likert-like scale

(for instance, selecting from the following categories the extent

of change of their acne after treatment: acne has worsened a lot;

worsened a little; stayed the same; improved a little; or improved

a lot).

(ii) Investigator-assessed change in lesion countThe change or percentage change from baseline in the number of:

• inflamed lesions (ILs) (papules or pustules or both)

• non-inflamed lesions (NILs) (blackheads or whiteheads or

both)

• nodules and cysts (for nodulocystic acne only)

If individual lesion counts are not available, then the change or

percentage change from baseline in the number of:

• ILs and NILs; or

• combined count of all lesion types.

Secondary outcome measures

(i) Investigator-assessed change in acne severityThe change in acne severity from baseline, using: a published grad-

ing scale (like the Leeds grading system, which involves counting

lesions and weighting them according to severity to give a com-

bined grade); or a severity index determined by the lesion count.

(ii) Investigator’s global assessment of improvementThis is likely to be recorded using a Likert or Likert-like scale. The

investigator’s assessment will be disregarded if it was performed

without using baseline photographs.

(iii) Changes in Quality of lifeAssessed using a recognised tool.

(iv) Investigator-assessed severe adverse effectsIf blistering or scarring of the skin follows treatment with light

therapy then we expect the severity of the adverse effect to be

reported, and whether it resolves in the short-term or is permanent.

Other adverse outcomes

We will record the incidence and severity of all other adverse events

reported in the included studies. We will use the system organ

classes (SOCs) defined in the latest version of medDRA (MedDRA

2007) .



Timing of outcome assessment

We will consider short-term (2 to 4 weeks), medium (5 to 8 weeks),

and long-term (longer than 8 weeks) follow-up periods. The long-

term data are the primary endpoint but we are also interested in

short-term data, indicating early improvement, which may en-

courage participants to continue with treatment .

Exclusion criteria

• Studies which were not RCTs;

• Studies not focused on the healing properties of light in the

management of acne;

• Studies on light therapies for acne scars.

Search methods for identification of studies

Electronic searches

With the help of the Cochrane Skin Group, we will search for

relevant published trials in:

The Cochrane Skin Group Specialised Register;

The Cochrane Central Register of Controlled Trials (CENTRAL)

in the latest issue of The Cochrane Library;MEDLINE (from 2005);

EMBASE (from 2007);

PsycInfo (from inception);

CINAHL (Cumulative Index to Nursing & Allied Health Litera-

ture) (from 1980);

LILACS (Latin American and Caribbean Health Science Infor-

mation database, from inception);

ISI Science Citation Index (on BIDS) ISI web of science;

Dissertation Abstracts International (1861).

The UK Cochrane Centre has an ongoing project to systemati-

cally search MEDLINE and EMBASE for reports of trials which

are then included in the Cochrane Central Register of Controlled

Trials. Searching has currently been completed in MEDLINE to

2004 and in EMBASE to 2006. Further searching will be under-

taken for this review by the Cochrane Skin Group to cover the

years that have not been searched by the UKCC.

The draft search strategy for MEDLINE (OVID) is shown in

Appendix 1. This will be adapted to include additional search

terms where necessary. A similar strategy will be used for EMBASE

and the other databases listed.

Ongoing Trials

We shall search for ongoing trials in the following trials registers:

The metaRegister of Controlled trials www.controlled-trials.com

The U.S. National Institutes of Health Ongoing Trials Register

www.clinicaltrials.gov

The Australian and New Zealand Clinical Trials Registry

www.anzctr.org.au

The World Health Organisation International Clinical Trials Reg-

istry Platform www.who.int/trialsearch

The Ongoing Skin Trials register www.nottingham.ac.uk/

ongoingskintrials

Searching other resources

Grey Literature

We shall attempt to find unpublished studies through searching

grey literature sources such as Internet search engines Google,

Google Scholar, and Copernicus.

Reference lists

We will look through the reference lists of published studies and

reviews for references to RCTs.

Correspondence

We will consult trial authors of included and excluded trials pub-

lished in the last 15 years and other experts in the field of optical

therapies for acne in order to identify unpublished RCTs.

Adverse Effects

We will not perform a separate search on adverse outcomes, but

will record adverse outcomes reported in the included trials and

discuss the implications of those adverse outcomes.

Language

We will not restrict the search to trials published in English only

and will arrange translation as necessary.

Data collection and analysis

Selection of studies

Two authors (MC and CL) will scan the titles and abstracts of

studies identified by the searches. If studies do not address the

study of a light therapy for acne we will exclude it. If any of the

authors feels that a paper could be relevant, it will be retrieved in

full text and each author will independently check that it meets

the pre-defined selection criteria, with any differences of opinion

being resolved by discussion with the review team. Those studies

that are excluded after reading the full paper will be listed in the

’Characteristics of excluded studies’ table.



http://http;//www.controlled-trials.com

http://http;//www.controlled-trials.com

http://www.clinicaltrials.gov

http://www.anzctr.org.au

http://www.who.int/trialsearch

http://www.who.int/trialsearch

http://www.nottingham.ac.uk/ongoingskintrials

http://www.nottingham.ac.uk/ongoingskintrials

Data extraction and management

Two authors (MC and FH) will independently record data using

a specially designed data extraction form. A third team member

(JC) will resolve any differences of opinion. One author (FH)

will then enter the data into RevMan. We will define treatment

success as anything above the first category of improvement on a

Likert scale, or more than 50% improvement from baseline on a

continuous scale.

All other outcomes will be recorded as the actual or percentage

change from baseline.

Assessment of risk of bias in included studies

We will assess the methodological quality of each included study

using the following criteria and record this information in the

’Risk of bias’ section within the ’Characteristics of included studies’

table:

a) how the randomisation sequence was generated;

b) whether allocation was adequately concealed;

c) whether participants, clinicians, or outcome assessors were

blinded as appropriate, who was blinded and not blinded (partic-

ipants, clinicians, outcome assessors) if this is appropriate;

d) how many participants were lost to follow-up, and whether

reasons for losses were reported;

e) whether the intention-to-treat principle was followed, where

participants are analysed in the groups to which they were origi-

nally randomised .

In addition we shall report on:

f ) the baseline comparisons of the participants for age, sex, dura-

tion, location, and severity of acne;

g) light source identity, dose, duration of treatment, and adequacy

of instructions if self-administered;

h) whether outcome measures were described and their assessment

was standardised;

i) whether previous acne treatment was discontinued in a timely

manner prior to the trial;

j) whether concomitant acne treatment was permitted, and if so

whether standardised;

k) the use and appropriateness of statistical analyses, where data

are not reported appropriately in the original publication.

Measures of treatment effect

We will express the results as risk ratio (RR) and 95% confidence

intervals (CI) for dichotomous outcomes. Mean differences will

be used for continuous outcomes with 95% CI, with standardised

mean differences being used where different but comparable mea-

sures have been used across trials, e.g. for quality of life. We shall

express the result as ’number needed to treat’ for dichotomous

outcomes where appropriate.

Unit of analysis issues

Where there are multiple intervention groups within a trial, we

will make pair wise comparisons of light therapies with different

wavelengths versus no treatment, placebo, and conventional treat-

ment. We will analyse internally controlled trials using appropriate

techniques for paired designs and these studies will not be pooled

with studies of other designs.

Dealing with missing data

If participant drop-out leads to missing data we shall conduct an

intention-to-treat analysis. We will contact trial authors or spon-

sors of studies which are less than 15 years old to provide missing

statistics such as standard deviations. For dichotomous outcomes,

we will regard participants with missing outcome data as treat-

ment failures and include these in the analysis. For continuous

outcomes, we will carry forward the last recorded value for partic-

ipants with missing outcome data.

Assessment of heterogeneity

We will assess statistical heterogeneity using the I2 statistic. If the I2 statistic is greater than 80% we shall synthesise data using meta-

analysis techniques.

Assessment of reporting biases

We will test publication bias by the use of a funnel plot when

adequate data are available for similar light therapies.

Data synthesis

For studies with a similar type of design, we will perform a meta-

analysis to calculate a weighted treatment effect across trials, using

a random-effects model. Where it is not possible to perform a

meta-analysis we will summarise the data for each trial.

Subgroup analysis and investigation of heterogeneity

If substantial heterogeneity (I2 > 50%) exists between studies for

the primary outcome, we will look for the reasons for this, such as:

differences in disease severity, exposure, and duration of treatment.

We will undertake further subgroup analysis if sufficient informa-

tion is given. The groups will include those with different severity

or onset of acne and the age of participants (child or adult).

Sensitivity analysis

We intend to undertake sensitivity analyses to determine the effects

of excluding the poorer quality trials, those with a moderate or high

risk of bias as defined in the Cochrane Handbook of Systematic

Reviews of Interventions (Higgins 2008).



Adverse outcomes

We will describe:

(a) whether the methods used to record adverse events were ap-

propriate;

(b) whether reporting of adverse outcomes was adequate.

Other

Where necessary, we will contact the trial authors for clarification.

We will use GRADEPro to create the Summary of Findings (SoF)

table.

A C K N O W L E D G E M E N T S

This protocol is based on the Cochrane protocol by Leonard T,

Eady A, Jordan J, Leonardi-Bee J. Complementary therapies for

acne vulgaris, 2006 (Leonard 2006)

The Cochrane Skin Group editorial base would like to thank Amy

Taub who was the External Content Referee, Jack Tweed the Con-

sumer Referee, Sue Jessop the Key Editor, Jo Leonardi-Bee the Sta-

tistical Editor, and Philippa Middleton the Methodology Editor

on this protocol.

R E F E R E N C E S

Additional references

Archer 2004

Archer JS. Hirsutism and acne in polycystic ovary syndrome.

Bailliere’s Best Practice & Research Clinical Obstetrics &

Gynaecology 2004;18:737.

Arowojolu 2004

Arowojolu AO, Grimes DA, Garner SE. Combined oral

contraceptive pills for treatment of acne. Cochrane Database

of Systematic Reviews 2004;CD004425:1–73.

Baldwin 2002

Baldwin HE. The interaction between acne vulgaris and the

psyche. Cutis 2002;70:133–9.

Böhm 1998

Böhm M, Luger TA. The Pilosebaceous Unit Is Part of the

Skin Immune System. Dermatology 1998;196(1):75–9.

Charakida 2004

Charakida A. Mouser PE. Chu AC. Safety and side effects of

the acne drug, oral isotretinoin. Expert Opinion on Drug

Safety. 3(2):119-29, 2004 Mar. [: 15006718]

Crawford 1979

Crawford WW. Laboratory induction and clinical

occurrence of combined clindamycin and erythromycin

resistance in Corynebacterium acnes. The Journal of

Investigative Dermatology 1979;72:187.

Cunliffe 1986

Cunliffe WJ. Acne and unemployment. British Journal of

Dermatology 1986;115(3):386.

Cunliffe 2004

Cunliffe WJ, Holland DB, Jeremy A. Comedone formation:

etiology, clinical presentation, and treatment. Clinical

Dermatology 2004;22:367–74.

Eady 1998

Eady EA. Bacterial resistance in acne. Dermatology 1998;

196:59.

Elman 2003

Elman M. The effective treatment of acne vulgaris by a

high-intensity, narrow band 405-420 nm light source.

Journal of Cosmetic and Laser Therapy 2003;5:111.

Friedman 2004

Friedman PM. Treatment of inflammatory facial acne

vulgaris with the 1450-nm diode laser: a pilot study.

Dermatologic Surgery 2004;30:147.

Garner 2003

Garner SE, Eady EA, Popescu C, Newton J, Li Wan Po A.

Minocycline for acne vulgaris: efficacy and safety. Cochrane

Database of Systematic Reviews 2003, Issue 1. UK DOI:

10.1002/14651858.CD002086. John Wiley & Sons, Ltd,

issue 1.

Goulden 1999

Goulden V, Stables GI, Cunliffe WJ. Prevalence of

facial acne in adults. Journal of the American Academy of

Dermatology 1999;41:577–80.

Goulden 2003

Goulden V. Guidelines for the management of acne vulgaris

in adolescents. Paediatric Drugs 2003;5:301–13.

Greenwood 1986

Greenwood R. Evaluation of a therapeutic strategy for

the treatment of acne vulgaris with conventional therapy.

British Journal of Dermatology 1986;114(3):353.

Gupta 2004

Gupta AK, Cooper E, Cunliffe WWC, Gover MD.

Oral isotretinoin for acne. Cochrane Database of

Systematic Reviews 2004, Issue 4. [DOI: DOI: 10.1002/

14651858.CD005026]

Higgins 2008

Higgins JPT, Green S (editors). Cochrane Handbook for

Systematic Reviews of Interventions Version 5.0.1 [updated

September 2008]. The Cochrane Collaboration. Available

from www.cochrane-handbook.org, 2008.

Jordan 2000

Jordan RE, Cummins CL, Burls AJE, Seukeran DC.

Laser resurfacing for facial acne scars. Cochrane Database

of Systematic Reviews 2000, Issue 3. [DOI: 10.1002/

14651858.CD001866]



Kilkenny 1998

Kilkenny M, Merlin K, Plunkett A, Marks R. The

prevalence of common skin conditions in Australian school

students. British Journal of Dermatology 1998;139:840–5.

Layton 1994

Layton AM, Henderson CA, Cunliffe WJ. A clinical

evaluation of acne scarring and its incidence. Clinical and

Experimental Dermatology 1994;19:303–8.

Leonard 2006

Leonard T, Eady A, Leonardi-Bee J. Complementary

therapies for acne vulgaris. Cochrane Database of

Systematic Reviews 2006, Issue 4. [DOI: DOI: 10.1002/

14651858.CD006262]

Leyden 1983

Leyden JJ. Propionibacterium acnes resistance to antibiotics

in acne patients. Journal of the American Academy of

Dermatology 1983;8:41.

Leyden 1997

Leyden JJ. Oral isotretinoin. How can we treat difficult acne

patients?. Dermatology 1997;195(Supplement 1):29–33.

Lloyd 2002

Lloyd JR. Selective photothermolysis of the sebaceous

glands for acne treatment. Lasers in Surgery and Medicine

2002;31:115.

Mariwalla 2005

Mariwalla K. Use of lasers and light-based therapies for

treatment of acne vulgaris. Lasers in Surgery and Medicine

2005;37:33.

MedDRA 2007

MedDRA MSSO. Medical Dictionary for Regulatory

Activities Terminology, Version 11.1 (MedDRA).

International Conference on Harmonization of Technical

Requirements for Registration of Pharmaceuticals for

Human Use (ICH) 2007.

Pfeifer 2005

Pfeifer SM. Polycystic ovary syndrome in adolescent girls.

Seminars in Pediatric Surgery 2005;14:111–7.

Poli 2001

Poli F, Dreno B, Verschoore M. An epidemiological study

of acne in female adults: results of a survey conducted in

France. Journal of the European Academy of Dermatology and

Venereology 2001;15:541–5.

Ross 2005

Ross EV. Optical treatments for acne. Dermatologic Therapy

2005;18:253.

Seaton 2003

Seaton E, Charakida A, Mouser P, Grace I, Clement R,

Chu A. Pulsed-dye laser treatment for inflammatory acne

vulgaris: randomised controlled trial. The Lancet 2003;362

(9393):1347–1352.

Seaton 2006

Seaton E. Investigation of the mechanism of action of

nonablative pulsed-dye laser therapy in photorejuvenation

and inflammatory acne vulgaris. British Journal of

Dermatology 2006;155:748.

Stathakis 1997

Stathakis V, Kilkenny M, Marks R. Descriptive

epidemiology of acne vulgaris in the community. Australian

Journal of Dermatology 1997;38:115–23.

Stern 1989

Stern RS. When a uniquely effective drug is teratogenic.

The case of isotretinoin. The New England Journal of

Medicine 1989;320(15):1007.

Tan 2004

Tan JK. Impact of acne vulgaris: evaluating the evidence.

Skin Therapy 2004;9:1–3.

Thiboutot 2004

Thiboutot D. Acne: hormonal concepts and therapy.

Clinical Dermatology 2004;22:419–28.

Thomas 2004

Thomas DR. Psychosocial effects of acne. Journal of

Cutaneous Medicine and Surgery 2004;8, Supplement 4:

3–5.

Webster 2002

Webster GF, Poyner T, Cunliffe W. Acne vulgaris,

Commentary: A UK primary care perspective on treating

acne. BMJ 2002;325:475–479.

Zouboulis 2004

Zouboulis CC. Acne and sebaceous gland function. Clinical

Dermatology 2004;22:360–6.∗ Indicates the major publication for the study



A P P E N D I C E S

Appendix 1. MEDLINE draft search strategy

1. randomized controlled trial.pt.

2. controlled clinical trial.pt.

3. randomized.ab.

4. placebo.ab.

5. clinical trials as topic.sh.

6. randomly.ab.

7. trial.ti.

8. 1 or 2 or 3 or 4 or 5 or 6 or 7

9. humans.sh.

10. 8 and 9

11. acne vulgaris.mp. or exp Acne Vulgaris/

12. lasers.mp. or exp Lasers/

13. seasons.mp. or exp Seasons/

14. sunlight.mp. or exp Sunlight/

15. ultraviolet therapy.mp. or exp Ultraviolet Therapy/

16. photolysis.mp. or exp Photolysis/

17. phototherapy.mp. or exp Phototherapy/

18. photochemotherapy.mp. or exp Photochemotherapy/

19. photosensitizing agents.mp. or exp Photosensitizing Agents/

20. 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19

21. 11 and 10 and 20

H I S T O R Y

Protocol first published: Issue 3, 2009

C O N T R I B U T I O N S O F A U T H O R S

Link with the editorial base (FH)

Draft the protocol (MC, FH, and AL)

Perform literature searches (JC and MC)

Identify relevant titles and abstracts from searches (MC and CL)

Select studies for inclusion (JC and MC)

Extract the data from the studies (MC and FH)

Resolve differences of opinion (JC)

Enter the data into RevMan and perform the meta-analysis (FH)

Draft the final review (FH)

Review and amend the text of the report as necessary (JC, AM, and AL)



D E C L A R A T I O N S O F I N T E R E S T

None known.

S O U R C E S O F S U P P O R T

Internal sources

• Members of the Department of Primary Care and Social Medicine, Imperial College, London, UK.

Access to libraries and MEDLINE, IT and statistical support, advice, and time to write this protocol.

External sources

• Dr Alison Layton, Consultant Dermatologist, Harrogate and District NHS Foundation Trust, North Yorkshire, UK.

For help and advice while writing this protocol.



cochrane database of systematic reviews (protocols) || light therapies for acne

Documents