Table 2.

Clinical studies evaluating hormonal treatment approaches in HS patients.

References	Study Design (Level of Evidence, Oxford Criteria [84])	Treatment Regimen	Efficacy Data/Results
Antiandrogen Treatments
Kraft et al., 2007 [94]	retrospective chart review patients (n = 64, all female) (evidence level: 3b)	various antihormonal treatments (n = 29) -ethinylestradiol 50 µg q.d. + CPA 25 mg q.d. -CPA 25 mg q.d. -Spironolactone 100 mg q.d. -CPA 25 mg q.d. + spironolactone 100 mg q.d.	-antiandrogen therapy superior to oral antibiotics (clinical response 55% vs. 26%) -prevalence of PCOS 38.1%
Sawers et al., 1986 [92]	case series (n = 4, all female) (evidence level: 4)	CPA 100 mg q.d. + ethinylestradiol 30–50 mg q.d.	-successful disease control in all patients -reduction of CPA dose led to HS deterioration in 75%
Mortimer et al., 1986 [93]	randomized double-blind crossover trial (n = 24, all female) (evidence level: 2b)	-ethinylestradiol 50 µg q.d. + CPA 50 mg q.d. -ethinylestradiol 50 µg q.d. + norgestrel 500 mg q.d.	-substantial improvement of HS in both treatment regimens; no significant difference -antiandrogen therapy may be beneficial in HS treatment
Spironolactone
Lee et al., 2015 [97]	case series (n = 20, all female) (evidence level: 4)	spironolactone 100–150 mg/d ± minocycline ± CPA	-clinical improvement (reduction of HS-PGA) in 85% after 3 months; complete remission in 55% -spironolactone was well tolerated and patients were satisfied with treatment
Golbari et al., 2019 [96]	retrospective single-center chart review (n = 67, all female) (evidence level: 4)	spironolactone 25–200 mg/d (average dose 75 mg/d)	-significant reduction of HS-PGA, pain and inflammatory lesions -no significant difference in HS improvement between spironolactone ≤75 mg/d and ≥100 mg/d
Quinlan et al., 2020 [98]	retrospective study (n = 26, all female) (evidence level: 4)	spironolactone 50–100 mg/d ± metformin	-reduction of DLQI >5 in 35% -no further clinical data
Metformin
Verdolini et al., 2013 [101]	prospective study (n = 25) (evidence level: 4)	metformin 1000–1700 mg/d over 24 weeks	-significant clinical improvement (reduction of Sartorius score and number of work days lost) in 72% -significant improvement of DLQI in 64%
Jennings et al., 2020 [99]	retrospective chart review (n = 53) (evidence level: 4)	metformin; mean dose 1.5 g/d; mean treatment duration 11.3 months	-subjective clinical response in 68%; complete remission of inflammatory skin lesions in 19% -insulin resistance present in 75%, but not predictive for treatment response
Moussa et al., 2020 [100]	retrospective study (n = 16, pediatric HS patients) (evidence level: 4)	metformin as adjunctive treatment (dose not specified)	-clinical improvement in 5/16 (31.3%); no improvement in 5/16 (31.3%); 6/16 patients (37.5%) lost to follow-up