Author

(year of publication)

Level of evide-nce

Study design

Patients (N)

Inclusion criteria

Follow-up

Outcome measures

Results

Lost to follow-up

Comments

Nd:YAG (and CO2)

Abdel Azim, 2018

B

RCT, intra-patient

N = 20 were randomized

4 sessions with 2 weeks interval of

I: one side = combined

Treatment of fractional CO2 laser and long pulsed Nd : YAG

(1064 nm) laser

C: other side = long pulsed Nd : YAG laser (1064 nm) only

>18 years with HS

Hurley’s stage I + II bilateral and almost symmetric lesions with one or more anatomic sites affected

Exclusion:

- Hurley’s stage III - Pregnant

and lactating women

– Patients with systemic diseases – usage of topical or systemic

medications, or laser therapy for HS within 2 weeks prior to

enrollment

3 months

Primary:

After 2 weeks post-treatment:

- objective photographs

- clinically: (subjective) PGA. Degree of improvement was calculated as the percentage of PGA 2 weeks after treatment to the PGA at the baseline.

- 10point VAS for patient’s

Satisfaction

- side effects.

- histopathologically: 3.5 mm lesional punch biopsy and histopathologic

examination using disposable punch

Secondary

After 3 months:

- recurrence post treatment (as activation of the previously

present lesion and/or appearance of a new lesion)

- Higher improvement and patient’s satisfaction was observed in combined treatment side compared with control side (P = 0.011, 0.048 respectively): mean degree of improvement in combined treatment side was 90% 20.52 SD with mean VAS = 8.05 1.84 SD, while mean

degree of improvement in Nd : YAG side was 70.68% 23.55

SD with mean VAS = 7 1.62 SD. PGA was clear

(score = 0) in 80% (n = 16) of the treated sides.

- Absence of recurrence was achieved by 55% of sides receiving combined treatment and 35% of control sides.

- histopathology: sparse perifollicular lymphohistiocytic

inflammatory infiltrate for combined treatment sides. Less reduction in the perifollicular

infiltrate and dermal edema for Nd : YAG sides compared with

combined treatment sides.

- No side effects were reported except for erythema that resolved

spontaneously within 48 hours post treatment.

N = 5 (25%)

- coin tossing for allocation concealment

- small sample size (didn’t math power calculation)

- single blinded

Mahmoud, 2010

B

RCT, within patient

Follow-up study description of Tierney, 2009

N=22

Intervention:

Half side body Nd:YAG laser plus topical regimen (same as control) monthly for

4 months

Control: contra lateral side topical

therapy in the form of benzoyl peroxide wash 10% and clindamycin 1% lotion.

Assessment: 4 monthly laser treatment.

Inclusion:

- patients

with HS Hurley stage II with bilateral and symmetric disease with

one or more anatomic sites of involvement

Washout period for patients, of both systemic

and topical therapy for 2 weeks before study initiation.

Exclusion:

concomitant

use of systemic treatments for HS, systemic

antibiotics and retinoids (stop 2 weeks beforestudy)

6 months by modified HS-HLA ad 5 months for histopathologic results.

- disease activity HS

Lesion Area and Severity Index

on Sartorius score

- Histologic examination (4 patients had biopsies)

- questionnaire for satisfaction

- Progressive improvement in disease activity maintained during follow-up: averaged over all

anatomic sites, the percent improvement was 72.7% on the laser treated side, and 22.9% on the control side (difference between treated side and control: P <.001).

Results for axilla and

inguinal folds were comparable. Inframammary results showed that decrease at the treated sites was not significant over the decrease at the control sites (P = .120).

- Histologic examination: no significant change immediately after

treatment with no evidence of thermal injury. 1 week after treatment an initial acute neutrophilic infiltrate. Granulomatous inflammation at follow up. An inflammatory infiltrate surrounded the hair shaft remnants, denoting destruction of hair follicles.

- satisfaction: pain:

77% less, 15% moderately less, 8% unchanged. 92% stated that it was more effective relative to other medical treatment such as topical and oral antibiotics, retinoids, and hormonal therapy, whereas 8% stated that it was equal.

5 (withrawal before treatment, pregnancy, cellulitis wherefore AB was needed)

- small sample size

- randomized by coin toss

Tierney, 2009

B

RCT, within patient

See also Mahmoud 2010 for follow-up study and histopathological results of 4 patients of this study set up

N=22

Intervention:

One half body site 1,064-nm Nd:YAG (4 times every month) and topical antibiotics (see control)

Control: contra-lateral half body topical antibiotics (benzoyl peroxide wash 10%, clindamycin

1% gel or 1% lotion)

Patients with stage II to III HS

Disease with bilateral and symmetric

disease with one or more anatomic sites of

involvement.

Exclusion: systemic and topical therapy during study. Otherwise wash out for 2 weeks before study initiation

4 months (1 month after last treatment)

- HS-LASI scale and modified HS-LASI (0-3) for patient symptoms (erythema, edema, pain, and purulent discharge); before each treatment and 1 month afterwards

Percentage improvement was calculated by comparing the HS-LASI and modified HSLASI

score

N=15 inguinal disease, N=12 axillary disease, N=7 inframammary disease;

Change in HS severity after 3 months was –65.3% over all anatomic sites, - 73.4% inguinal, - 62.0% axillary, and - 53.1% inframammary. For all anatomic sites combined and each individual anatomic site, the change in HS severity from baseline to month 3 was statistically significant at the treated sites (p<.02 for modified HS-LASI and HS-LASI) but not at the control sites (p<.05 for modified HS-LASI and HS-LASI).

Improvement in HS-LASI

score was significantly greater on the laser-treated side than on the control side for the axillary and

inframammary sites. Continued progression of improvement in HS-LASI score was observed with each subsequent Nd:YAG laser treatment, with the greatest overall change in HS-LASI score

between baseline and month 1 for all anatomic

sites treated (p<.05, change in HS-LASI score

baseline vs month 1 relative to all other monthly time intervals.)

5 (withrawal before treatment, pregnancy, cellulitis wherefore AB was needed)

- small sample size

- randomized by coin toss

- time points of assessment not exactly clear: results describe as 3 months, but studt set up for 4 months. Probably results are from one months after last treatment.

Xu, 2011

B

RCT, within patient

From same study group as Mahmoud 2010 and Tierney 2009

N = 20

Intervention: Long-Pulsed 1064-nm

Nd:YAG Laser

Control: depending on number of anatomic sites: 1 anatomic site = no treatment at contralateral side, 2 anatomic sites = other anatomic site serves as untreated control.

Four-millimeter skin punch biopsy specimens: active lesions on the treated site before laser treatment, after 24 hours (for the first 7 specimens) and at day 7, day 30, and day 60 (for all patients). On day 60, an active lesion

from an untreated site was biopsied as control.

Patients with Hurley stage II disease

Exclusion:

- concomitant

use of systemic treatments for HS, which must be discontinued

for 2 weeks prior to start of the study

- exacerbation

of the patient’s original condition expressed clinically by

a shift from Hurley stage II to stage III.

Topical treatments were allowed.

2 months

Modified HS-LASI

described by Sartorius et al (see Tierney 2009 and Mahmoud 2010)

with patients symptoms (erythema and edema by VAS).

Percentage of improvement calculated by comparing modified HS-LASI score at baseline with the score at each laser treatment (on days 30 and 60).

Histopathologic changes, clinicopathologic correlation

- overall anatomic sites:

–31.6% (P<0.001) change in HS-LASI, mean HS-LASI scores 2 months vs baseline axilla: 17.2 (6-28) vs 23.7 (9-34); inguinal 22.6 (0-49) vs 38.6 (6-100).

- Histopathological changes: increased inflammation at 1 week after treatment and decreased inflammation with resulting fibrosis

and scarring at 1 month and 2 months after treatment.

- Response of 15/18 transitioned from a

marked superficial and deep inflammatory response seen

on pathologic findings at baseline to a minimal inflammatory

response (mainly deep if present) and/or scarring

and fibrosis seen at 2 months after laser treatment.

This change at the microscopic level corresponded with

a decrease in the HS-LASI scores of these patients (ns).

1

- small sample size

- randomization by anatomic site of disease:

bilateral axilla, inframammary region or groin.

- change in time points for assessment of histopathologic examination (7 patients after first 24 hours and 12 patients after 1 week in stead of 24 hours). No data of controls.

Diode laser

Fabbrocini, 2018

C

Retrospective study, open clinical study

N = 20

Intervention: Diode laser with a wavelength of 1064nm in pulsed operation; four laser sessions, one every two weeks.

Not clearly stated:

HS patients aged between 18 and 44 years were conducted

- wash-out period from any topical and systemic medications.

Exclusion:

Patients with significant comorbidities and those who were pregnant.

At baseline and after 8 weeks:

- Hurley stage

- Sartorius score

- PGA

Responses were classified as complete (improved by 65% or more), good (between 40% and 65%), partial (between 15% and 40%) and no response (less than 15%).

- HiSCR

- DLQI

- 50% of patients had a Hurley stage I, while the remaining subjects had a Hurley stage II; no patient with Hurley stage III was recruited.

- Each patient significant reduction (31%) of Sartorius score from 28.55 ± 13.04 to 19.75 ± 12.29 after 4 laser sessions (p < 0.05)

- HiSCR was achieved in 13 patients (65% of patients). 60% of patients with Hurley II and 80% patients with Hurley I

- DLQI values reduction (p = 0.0307)

- Adverse effects included postoperative pain, erythema, and mild swelling. One patient complained of fever and an influenza-like illness, which resolved itself. Serious adverse side effects, suppuration or infections did not occur.

unknown

- Not classic comparative study set-up; no control group

- small sample size

IPL

Fadel, 2015

B

RCT, intra-patient

N = 11 were included (6 excluded)

Both using IPL with a 630 nm filter

Intervention: one side niosomal MB

(NMB) gel

Control: unloaded (free) MB (FMB) gel.

All stages of HS (by Hurley grade)

Exclusion:

- isotretinoin use in the previous

6 months

- pregnancy or lactation

- history of

photosensitivity

6 months

Modified HS-LASI

Lesions at Hurley stage 3 showed variable degree of improvement.

Mild improvement was obtained in one patient

with extensive fibrosis while moderate

improvement was obtained in another patient. There was a significant reduction in HS-LASI scores after both treatments.

NMB gel produced a higher percentage reduction in lesion size compared with FMB gel (77.3 18.86% vs. 44.1 28.19%, respectively) which was statistically significant (P < 0.01). There was no significant correlation between anatomical site, disease

stage and number of treatments. There were no reports of pain, erythema or hyperpigmentation. Two

patients developed new lesions at the FMB-treated sites on the buttocks 3 months after treatment cessation,

and one FMB-treated patient experienced relapse of HS in the axilla 6 months after treatment cessation.

1

- small sample size

- single blinded

 – randomization by tossing a coin

Highton, 2011

B

RCT, within patient

N = 18

Intervention: IPL of one axilla, groin or inframammary area 2x/wk for 4 wks (Harmony Laser)

Control: contralateral side untreated

Assessment: before and

after treatment and then at 3, 6, and 12 months.

Inclusion

Criteria:

adults with Hurley stage II or III HS with bilateral axillary,

groin, or inframammary disease.

Exclusion:

using topical or systemic therapy for 2 weeks before the first treatment.

1 year

- response to treatment by Hidradenitis Suppurativa Examination

Scoring System from Sartorius et al:

Type of lesion, longest distance between two lesions, lesions separated by normal skin, erythema, discharge, max 24 points)

- alidated examination

and clinical photographs

- patient satisfaction on a Likert scale.

N=12 axillary

disease, n=4 groin disease, n=2 inframammary disease.

Change in HS examination score (IPL vs control) significant improvement in the mean examination score that was maintained at 12 months (p 0.001, logistical regression analysis): after treatment -55% vs 12%, 3 months –56% vs -10%, 6 months –44% vs -10%, 12 months –33% vs 3%. The improvement was confirmed by independent assessment

of clinical photographs (interrater reliability, 0.79; p 0.001).

- The experts

detected an improvement in the signs of HS on the treated side but

no change on the control side, with high interrater reliability (kappa= 0.79, p< 0.001).

- Patients reported high levels of satisfaction with the treatment.

1 (painful treatment)

- small sample size

- single blinded

Photodynamic therapie (PDT)

Schweiger, 2011 (alleen gegevens uit abstract)

C

open-label, non-blinded study

N =12

Intervention:

photodynamic therapy with aminolevulinic acid: two blue light sources and intense pulsed light (IPL): once weekly for four weeks

Active HS

More than 12 weeks

Efficacy and safety:

- Number of lesions

- Global severity score

- DLQI

- Mean lesion counts were 11.25 at baseline, 6.5 at 4 weeks (50.8% reduction), and 7.5 at 8 weeks (29.9% reduction).

- Three subjects (25%) had complete clearance and no active lesions 4 weeks after the final treatment

- Mean Global Severity Scores were 2.2 at baseline, 1.5 at 4 weeks, and 1.8 at 8 weeks.

- Mean DLQI scores were 17.3 at baseline, 13.1 at 4 weeks (27.2% improvement), 14.00 at 8 weeks (19.3% improvement) and 14.0 (19.3% improvement) at the final week (16-62 weeks).

3

- Abstract only

- non blinded

- study set up unknown

Suárez Valladares, 2017

C

Retrospective study, case series

N=38

Intervention:

intralesional

photodynamic therapy with 5-aminolevulinic acid and 630 nm

laser beam

HS patients

recruited and treated at the Dermatology Department of Complejo

Asistencial Universitario de León (Spain) between March 2011 to Nov 2015.

52.6% overweight or obese, 89.5% active smokers at the time of the treatment.

5.3% treatment-naïve and 23.7% had also been treated with surgical

methods.

unknown

- Disease severity by Hurley score

- DLQI

- HSS

- VAS 1-10 in pain

- time to recovery: days taken off before returning to work

or normal routine.

- Hurley score I: 4 (10.5%)/II: 21 (55.3%)/III: 13 (34.2%)

- 76.3% (29/38) achieved a complete response, while persistence was noted on 8 cases and 1 suffered a recurrence. Difference between basal (median 28.5) and

final (0) HSS showed a significant reduction of 24.5 points (p < 0.001, 95% OR 19.5-31).

- Basal (median 10) and final (1) DLQI scores reached a reduction of 10 points (p < 0.001, 95%OR 8-12).

- VAS points 3 (2-5.25)

- Time to recovery 1 (1-2)

- Complete response was achieved in 68.2% of armpits, 88.5% of groins, 88.9% of buttocks and 100% of other locations.

- 47.3% (18/38) patients needed only one session to achieve a complete response, while maintaining a good tolerability.

- Treatment failures (n=9) lower percentage of obesity (33.3% vs 58.6%) and smoking habit (66.7% vs 96.6%) but a more severe initial disease (Hurley stage III 44.4% vs 31%), basal HSS score (36 vs 22) and basal DLQI values (16 vs 10).

unknown

Follow-up time mean 26.21 months (21.07-68.57)

Valladares-Narganes, 2015

C

Interventional study

N=27

Intervention:

Intralesional PDT

5-aminolaevulinic acid in saline at a concentration

of 1% was administered at a dose of 0.2 mL/cm3 of fistula, with a canula in sinus tracts or directly intralesional.

Lesion were intralesionally irradiated with a 630-nm laser diode to 1 Watt cm3 for 3 min (180 joules).

Those patients who showed a suboptimal response,

or who had new lesions near the treatment site, received a

further treatment session.

HS patients were recruited from March 2013 to November 2013.

No washout period.

Exclusion:

- Significant comorbidities

- Pregnancy

1, 3, 6 months

- modified Sartorius scale score:

complete (improved by

75% or more), good (between 50% and 75%), partial

(between 25% and 50%) and no response (less than 25%).

- VAS pain score (0-10)

- Adverse events

- 10 (37%) complete responses,

11 (41%) good responses and 5 (19%) partial responses.

- Pain: 1 patient experienced severe pain

(score 9). Moderate pain in 4 patients (visual analogue scale value 6–9).

- Adverse effects included postoperative pain, erythema and mild swelling.

1 nonresponding patient

No randomization

Vossen (a), 2018

C

Retrospective, case serie

N=25

Intervention: long-pulsed 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG)

HS patients with the follicular sub-phenotype

and mild disease (HS-PGA 2, Hurley stage IA)

July 2011 - December 2016 in the dermatology department

of the Erasmus University Medical Center (Rotterdam, The

Netherlands)

Reported follow-up (in months) 14.9 ± 14.1

A questionnaire was sent to assess patient reported outcomes.

Primary:

- Number of HS flares per month

Secondary:

- disease severity: NRS scale 0-10 (no suffering -extreme/unbearable suffering)

- overall treatment satisfaction: NRS scale 0-10 (very dissatisfied to very satisfied)

- quartile grading scale for decrease of hair growth in the treated area

- Nd:YAG depilation resulted in a decrease in the number of monthly flares (p = 0.019)

- The mean HS disease severity after depilation was significantly lower

than before therapy, NRS 6.4 ± 2.8 versus NRS 3.6 ± 3.5 (p = 0.010) respectively

- Overall treatment satisfaction NRS score: 6.7 ± 2.4

- The majority of patients reported a 51 % – 75 % decrease of hair growth after treatment

10 (no response or declined)

2 excluded because of suboptimal treatment

- no control group

Vossen (b), 2018

C

Intra-patient RCT

N=9

Intervention:

Single miraDry treatment (5.8 GHz, energy level 5, manufacturer’s recommended settings) in one axilla under tumescent anesthesia.

HS patients with a total abscess and nodule (AN) count between 3-5 per axilla with no more than one abscess or draining sinus.

3 months

Primary:

left-right comparison of the axillary areas using the Hidradenitis Suppurativa Clinical Response (HiSCR).

Secondary:

- numerical rating scale (NRS) on pain per axilla, - treatment satisfaction,

- hair follicle

17. ount.

- 2 patients reached HiSCR in miraDry treated axillae

- 2 patients reached HiSCR in contralateral axilla (p=1)

- 5 patients experienced worsening of their disease after miraDry treatment.

- active lesions during median 43 days (IQR 4-90) in miraDry treated axilla versus 5.5 days (2-26) in untreated axilla (p=0.14)

- Median NRS (IQR)

after 3 months was 7.0 (2.0-8.0) in the treated axilla versus 0 (0-5.0) in the untreated axilla (p=0.07).

- Lower number of hair follicles in the

miraDry-treated axilla (median 4.0 cm-2, IQR 3.0 – 5.0; -50.9% from baseline), compared with the

untreated axilla (median 8.5 cm-2, IQR 6.0 – 10.0; -2.0% from baseline), P=0.07.

1 excluded due to extreme pain during miraDry procedure

1 drop out due to worsening HS symptoms in treated axilla

Study was discontinued due to negative clinical outcomes during recruitment period.

Only 8 of the 20 recruited patients were treated.