Table 1.

Basic characteristics of studies included in the review

Study, year, country, type	Ptsa on MTFb Sex, age	Weight, diabetes, PCOSc	Hurley stage	Monotherapy, dose	Control group	Txd duration	Follow-up duration	Tx outcome	Adverse events
Arun and Loffeld (2009) [3], UK, case report	1 (fe) 50	146 kg Type II diabetes No PCOS	NRf	Yes 500 mg odg for 3 months, then 1 g od	No	NR (>4 months)	4 months	Less frequent and shorter flares at 3 months, no leaking of previously persistent left-axilla fistula and reduced pain at 4 months	None
Verdolini et al. (2013) [2], UK, prospective	25 (22 f) 31.5 (17–49)	22 f pts were “moderately overweight, had impaired glucose tolerance and PCOS” (no diabetics)	NR	Yes 500 mg od for a week, 500 mg bdh after a week, and then 500 mg tdsi after a week	No	“Most patients continued on the treatment well past the trial”	24 weeks	SSj mean±SDk dropped from 30.1 ±9.2 to 18.4±7.2 (p < 0.0001). DLQI'sl mean±SD dropped from 13.6±4.2 to 6.3±5.5 (p < 0.000001) Lost work-days dropped from 1.5 per month to 0.4	Mild Glm disturbance at the beginning of treatment
Sanz Bueno et al. (2017) [8], NFn	11 (5 f) NF	NF	NF	Yes Doses ranging from 450 to 2,550 mg daily	No	NF	24 weeks	SS ≥30% reduction in 2 pts Glucose tolerance normalization in 5 pts DLQI improvement in 4 pts (median reduction 5.5 points) DLQI increase in 4 pts (median increase 4.2 points) 2 pts discontinued tx because of more severe flares	Mild Gl discomfort (number of pts NR)
Jennings et al. (2019) [1], Ireland, retrospective	53 (45 f) 37 (19–62)	mean weight 102 kg (67–160 kg) 4 diabetes 5 PCOS	I 4% II 72% III 24%	Yes 500 mg od and then bd after 2 weeks (further increases applicable) – mean daily dose 1.5 g/day	No	11.3 months (mean) (1–36 months)	At least 3 months	19% complete response (no active HS) – only HIIp 58% of HII and 55% of HIIIq significant partial response 68% subjective clinical improvement Non-significant CRPr reduction 25% stopped due to non-response 21% needed 2nd agent	Gl complaints (6 patients) (3 stopped tx)
Moussa et al. (2020) [6], USA, retrospective	16 peds pts NF NF	NF	I 69% II 31%	No	No	NF	NF	5 pts improved (decreased flare frequency) 5 pts did not improve 6 pts were lost to f/ut 1 pt stopped tx due to lack of improvement	Gl distress and mood changes (2, stopped tx)
Segura Palacios et al. (2021) [7], Spain, retrospective	27 (18 f) 32.1	70.4% overweight or obese NR NR	I 51.8% II 48.2%	Yes between 1.7 and 2.55 g per day	No	At least 12 weeks	24 weeks	DLQI reduction (median: 13 to 9), p = 0.001 No significant PGAu reduction	Gl complaints (3 pts stopped tx because of them)

^aPts: patients.

^bMTF: metformin.

^cPCOS: polycystic ovarian syndrome.

^dTx: treatment.

^ef:female.

^fNR: not reported.

^god: once daily.

^hbd: twice daily.

ⁱtds: three times daily.

^jSS: Sartorius score.

^kSD: Standard deviation.

^lDLQI: Dermatology life quality index.

^mGI: Gastrointestinal.

ⁿNF: Not found.

^oEADV: European Academy of Dermatology and Venereology.

^pHII: Hurley stage II.

^qHIII: Hurley stage III.

^rCRP: C-reactive protein.

^sped: pediatric.

^t:f/u: follow-up.

^uPGA: Physician Global Assessment.