The link between tobacco smoking and HS has been suggested in several studies. In a retrospective study, 92.2% of HS patients were smokers and clinical remission was more often reported among non-smoking patients [42]. Moreover, Sartorius et al. found lower disease severities, evaluated by the mSS, in non-smokers compared to active smokers [27]. At a molecular level, components of cigarette smoke have been demonstrated to further promote inflammation in HS via inhibition of the already compromised Notch signaling, induction of proinflammatory cytokine expression and causing infundibular epithelia hyperplasia and hypercornification [43,44]. Although clear evidence of tobacco as a trigger of HS has not been found yet, patients should be encouraged to quit smoking [20].

Overweight and obesity are considered as frequent comorbidities of HS. In two case–control studies an increment of the likelihood of HS with every BMI unit increase was reported [45]. In another retrospective study, the point prevalence of HS was much higher in an obese study population compared to the general population [46]. This may be explained by changes of the skin microbiome and increased friction of skin folds in obese patients [47,48]. However, evidence for improvement of HS after body weight reduction is limited. A retrospective study reported a significant reduction of inflammatory activity in HS patients undergoing bariatric surgery [46,49]. Moreover, obese HS patients reported lower remission rates than non-obese HS patients [42].

Obese patients should be motivated to reduce their body weight by initiating physical activity and dietary changes [50]. In cases of severe obesity, bariatric surgery may be an option [51].

Due to its chronic recurrent course with painful lesions and purulent discharge, HS has a pronounced impact on the patient’s life and professional support may be required. Esmann et al. described an increased risk of social isolation due to shame and fear of stigmatization [52]. Quality of life can be severely affected by HS and HS has been observed as one of the most distressing conditions in dermatology [53,54]. HS is associated with an increased risk for distinct psychiatric disorders including depression, anxiety disorders and substance-related abuse [55]. Moreover, a meta-analysis found a more than two-fold increased risk for suicide in HS patients [55]. For this reason, physicians treating HS patients should perform a screening for psychiatric comorbidities and initiate psychiatric referral if necessary.

In cases of mild-to-moderate disease with limited extent, topical therapy can be considered. Topical clindamycin 1%, applied twice daily on involved areas, is the first-line treatment option for mild-to-moderate disease, especially in absence of deep inflammation or sinus tracts [20,56]. In a small prospective study, topical clindamycin effectively reduced inflammatory lesions compared to placebo [57]. In case of refractory disease after three months of treatment, other treatment options should be considered [20].

Resorchinol is a topical agent with keratinolytic, antipruritic and anti-inflammatory properties and can be applied twice daily on active inflammatory lesions [20]. In a retrospective study with 134 patients, topical resorchinol showed a significant improvement of HiSCR and pain compared to topical clindamycin use [58]. A case series assessing the efficacy of topical resorchinol for mild HS reported significant reduction of inflammatory activity and pain in all treated patients [59].

A current phase II study assesses the efficacy of the topical JAK1/JAK2-inhibitor ruxolitinib (NCT 04414514) [60].

Intralesional injections with glucocorticosteroids as triamcinolonacetonid can be considered for the treatment of solitary acute inflammatory nodules, when rapid reduction of inflammation is desired [61,62]. Clinical response with reduction of inflammation is regularly seen after 48–72 h [20].

Zinc salts (zinc gluconate) show anti-inflammatory effects in HS, probably through inhibition of chemotaxis of neutrophil granulocytes, modulation of cytokine expression and anti-androgen properties [63]. In HS, a high-dose therapy with 90 mg zinc gluconate per day in gradual dose escalation can be considered as a maintenance therapy for limited disease [20]. In several small studies, zinc gluconate showed promising results in mild-to-moderate HS [64,65,66]. As zinc competes with copper in gastrointestinal resorption, long-term use of high doses of zinc may cause hypocupremia and anemia; thus, routine monitoring of copper levels and hemoglobin is recommended [67]. Gastrointestinal discomfort is a frequent reported side effect.

Patients with refractory disease under topical therapies or with severe inflammation activity are potential candidates for systemic antibiotic therapy. A current study assessed the duration of antibiotic treatments in HS patients and showed that in the majority of oral antibiotic courses the duration of treatment was less than 12 weeks [68].

Recent guideline recommendations recognize tetracyclines as the first-line treatment for more widely spread HS in Hurley stage I/II [20]. Established tetracycline antibiotics include tetracycline, doxycycline and minocycline [69]. A prospective study comparing the efficacy of the different tetracycline antibiotics tetracycline, doxycycline and lymecycline showed a reduction of HSS in all treatment groups with greatest response in the tetracycline group. Moreover, a reduction of pain, formation of new inflammatory lesions and an improvement of quality of life was observed in all treatment groups [70].

An antibiotic combination therapy with clindamycin and rifampicin is recommended as first-line therapy for patients with Hurley stage II and moderate-to-severe disease and as second-line therapy for patients who do not respond on oral tetracycline treatment [20,56]. In an open-label prospective study with 56 patients, the combination of clindamycin and rifampicin showed an overall clinical response with reduction of HSS in 79.6%. HSS₅₀ was 37% and complete remission (HSS₁₀₀) was observed in 13%. Side effects were observed in 55.6% of patients with diarrhea, abdominal pain and nausea being the most commonly reported [71]. This data is strengthened by several retrospective trials, which came to similar results; however, the majority of patients with initial complete remission relapsed after discontinuation of treatment [72,73,74]. However, due to the role of rifampicin as a potent inductor of the hepatic CYP system, metabolization of clindamycin is intensified within the combination therapy [75,76]. In one study clindamycin blood levels were decreased by around 90% within two weeks after treatment initiation, raising the question of whether the observed response rates under combination antibiotic therapy may be traced to rifampicin alone [77,78]. More research with prospective randomized trials is needed to address this topic.

For more extensive disease with severe inflammation and widespread distribution of inflammatory lesions some intensified antibiotic treatment regimens have been described; however, up to now evidence is based on case report and retrospective analyses, and these therapies have not been evaluated in prospective trials.

Join-Lambert et al. described a broad-spectrum antibiotic combination therapy consisting of rifampicin, moxifloxacin and metronidazole leading to high rates of complete remissions, defined as clearance of all inflammatory lesions, especially in Hurley stage I/II patients [79].

Ertapenem, another broad-spectrum antibiotic, showed rapid improvement in treatment-refractory cases of HS as a rescue therapy [80]. In a retrospective pilot study with 30 patients, a 6 week course of ertapenem led to a significant and sustained improvement of disease severity, assessed with the Sartorius score [81]. Through its rapid clinical improvement, ertapenem may be initiated in severe HS as neoadjuvant therapy for bridging to surgery or other maintenance therapies [80,82,83].

Clinical observations in female HS patients with premenstrual flares and cyclic alterations of inflammation activity led to the suggestion that hormonal alterations may influence the course of HS [88]. Moreover, HS is associated with endocrine disorders such as polycystic ovary syndrome (PCOS) and metabolic syndrome [89,90]. However, the role of hormonal influences on the pathogenesis of HS is still unclear [91]. Most data regarding antiandrogenic treatment approaches for HS are based on retrospective analyses, and case reports and prospective trials are rare.

Successful disease control with an antiandrogenic therapy containing ethinylestradiol and cyproteronacetate (CPA) has been described in a case series [92]. In a double-blind controlled cross-over trial comparing two contraceptive regimens containing ethinylestradiol and norgestrel or cyproterone acetate, both treatments produced substantial improvement of disease activity; however, there was no significant difference [93]. In a retrospective study, Kraft et al. compared an antiandrogen treatment approach with antibiotic therapies in 66 female HS patients and found significantly superior response rates, 55% vs. 26%, suggesting that antiandrogen therapy should be considered for all women presenting with HS. Moreover, the authors concluded that female HS patients should be investigated for underlying PCOS and insulin resistance [94].

Spironolactone is a potassium-sparing diuretic with antiandrogen properties due to the inhibition of mineralocorticoid receptors [95]. In several retrospective analyses of female HS patients, spironolactone treatment led to a significant reduction of pain and inflammatory lesions, and improved quality of life [96,97,98].

The antidiabetic agent metformin reduces insulin resistance by improving peripheral insulin sensitivity and may have some antiandrogen properties [83]. In several retrospective trials and case reports, metformin showed promising clinical response rates and thus may contribute to disease control in HS as an adjunctive treatment option [99,100,101].

Retinoids influence cell differentiation and may have a beneficial impact in HS by reducing keratinocyte proliferation and subsequently preventing the plugging of the pilosebaceous unit [20]. Moreover, retinoids show anti-inflammatory properties by modifying monocyte chemotaxis [102]. The most common adverse events are retinoid dermatitis and, among women, hair loss. Retinoids have a teratogenic effect and effective contraception must be ensured in patients prior to treatment initiation [20].

Acitretin has been evaluated for the treatment of moderate-to-severe HS in a small prospective trial with 17 patients and showed an overall response rate of 47%; however, another 47% of patients dropped out due to lack of efficacy or adverse events [103]. In a retrospective study with 12 patients, acitretin showed promising results with all treated patients achieving clinical remission and reduction of pain [104]. Another recent retrospective cohort study reported significant clinical responses under acitretin treatment and identified the follicular HS phenotype, a history of follicular plugging diseases and a family history of HS as potential predictive markers for treatment response [105].

Isotretinoin has only shown limited efficacy for treatment of HS and several retrospective studies reported treatment response rates between 16.1% and 35.9% [106,107,108]. Clinical exacerbations and occurrence of new flares of HS have been reported after initiation of isotretinoin in various cases, which could be explained by the further reduction of the size and action of sebaceous glands due to isotretinoin therapy [109,110].

In recent years, interleukin 17 (IL-17) has emerged as a major player in various autoimmune and inflammatory skin disorders, and its proinflammatory isoforms IL-17A, IL-17C and IL-17F are presumed as key cytokines in HS [142,143]. IL-17A and IL-17F are mainly produced by T-helper 17 cells (T_H17) and play a major role in control of many fungal and bacterial infections, while IL-17C is released by epithelial cells like keratinocytes, and promotes further inflammation by mediation of the production of other inflammatory molecules and further enhancing the inflammation cascade through stimulation of IL-17A and IL-17F production in T_H17-cells as a feed forward loop [144,145].

The first evidence for the role of IL-17 in HS was reported by Schlapbach et al., who found a 30-fold increased expression of IL-17A in HS lesions compared to healthy skin [146]. Another study confirmed these findings and identified a dysregulated cytokine milieu in perilesional skin, suggesting that subclinical inflammation may be present in HS skin prior to the formation of active lesions [147]. Moreover, Navrazhina et al. found significantly increased expressions of the proinflammatory IL-17 isoforms A, C and F in lesional, perilesional and even unaffected skin of HS patients compared to healthy individuals [148]. Given these accumulating findings pointing toward a key role of IL-17 signaling in the pathogenesis of HS, targeting the IL-17 pathway seems like a promising treatment approach. However, as HS can be associated with inflammatory bowel disease, it should be kept in mind that paradoxical exacerbations of pre-existing IBD have been reported under anti-IL17 treatment [90,149].

Secukinumab is a recombinant human monoclonal IgG1κ antibody that selectively targets IL-17A and blocks its interaction with the IL-17 receptor [150]. In an open-label pilot study with nine patients, 78% reached HiSCR after 24 weeks of treatment with secukinumab 300 mg every 4 weeks [151]. Another open-label trial with 20 enrolled patients tested two dose levels of secukinumab (300 mg every 2 or 4 weeks after an initial loading dose) and observed pooled HiSCR rates of 70%. Interestingly, clinical responses were also observed in patients with failure to prior anti-TNF⍺ treatment [152].

Recently, the first results of two randomized, placebo-controlled, multicenter phase III trials (SUNSHINE, SUNRISE) evaluating the efficacy of secukinumab in two dose regimens (every 2 weeks or every 4 weeks) have been presented. After 16 weeks, the primary endpoint was reached in both studies for the every 2 weeks (Q2W) regimen and in one for the every 4 weeks (Q4W) regimen, demonstrating the superiority of secukinumab over placebo in patients with moderate-to-severe HS (HiSCR rates: 45% vs. 33.7% (study 1) and 42.3% vs. 31.2% (study 2) for secukinumab 300 mg every 2 weeks, and 41.8% vs. 33.7% (study 1) and 46.1% vs. 31.2% (study 2) for secukinumab every 4 weeks). In both treatment groups secukinumab significantly reduced inflammatory lesions and pain, and improved patients’ quality of life [153].

Bimekizumab is another humanized IgG1κ monoclonal antibody, targeting IL-17A and IL-17F. In a recent double-blind, placebo-controlled, phase II clinical trial (ClinicalTrials.gov NCT03248531) 90 patients were randomized to receive bimekizumab (640 mg at week 0, 320 mg every 2 weeks), adalimumab (160 mg at week 0, 80 mg at week 2 and 40 mg every week for weeks 4–10) or placebo. HiSCR was reached in 57.3% of the bimekizumab group compared to 26.1% in the placebo arm. Moreover, 46% of the patients under bimekizumab achieved HiSCR₇₅ and 32% achieved HiSCR₉₀, compared to 10% and 0% in the placebo group, respectively [34]. These promising results led to the initiation of three placebo-controlled phase III studies, which are currently ongoing (NCT04901195, NCT04242498, NCT04242446).

Nanobodies represent a novel innovative class of antibody-derived targeted therapies. Consisting of one or more domains based on the small antigen binding variable regions of heavy chain antibodies, they are much smaller compared to conventional monoclonal antibodies, facilitating their tissue penetration [154]. Moreover, several nanobodies can be linked to obtain multi-specific molecules [154,155].

Sonelokimab is a trivalent nanobody containing three domains with specificity for IL-17A, IL-17F and human serum albumin, and has already showed clinical efficacy in the treatment of plaque psoriasis in a recent phase II study [156]. An ongoing randomized placebo-controlled trial evaluates the efficacy of sonelokimab in patients with moderate-to-severe hidradenitis suppurativa (ClinicalTrials.gov NCT05322473) [157].

Izokibep, another small, molecular, antibody-mimetic IL-17A inhibitor has recently shown significant clinical responses in patients with psoriatic arthritis and is currently in a placebo-controlled phase II trial in HS (ClinicalTrials.gov NCT05355805) [158].

The proinflammatory interleukin-1 pathway is involved in promoting inflammation in HS and IL-1β has been shown to be significantly overexpressed in lesional skin of HS patients [159]. As the primary circulating isoform, IL-1β is expressed by macrophages, monocytes and dendritic cells due to activation of pattern recognition receptors in an inflammasome-dependent process [160]. IL-1β induces the expression of molecules promoting remodeling of the extracellular matrix and immune cell infiltration, making it a potential target for future HS treatments [159].

Anakinra is a recombinant IL-1 receptor antagonist, preventing its interaction with the ligands IL-1⍺ and IL-1β [161]. In a phase II placebo-controlled trial, HiSCR rates of 78% have been described after 12 week treatment compared to 30% in the placebo group; however, the majority of patients relapsed after treatment discontinuation [162]. Another prospective open-label study with five patients reported clinical improvements of inflammation activity and quality of life after an 8 week course of anakinra [163]. Several case reports described inconstant clinical responses with partial improvements and failure of anakinra treatment [140,164,165,166,167].

Bermekimab (also known as MABp1) is a recombinant monoclonal antibody that neutralizes IL-1⍺. In a prospective randomized controlled phase II trial, patients with moderate-to-severe HS, that were not eligible for or failed a prior anti-TNF⍺ treatment, showed significant clinical responses with HiSCR rates of 60% compared to 10% in the placebo group after 12 weeks [168]. Patients who were initially randomized to the placebo group were allowed to continue in an open-label extension study and 75% showed clinical response (HiSCR) after 12 weeks of bermekimab treatment [169].

In another phase II study with 42 patients with moderate-to-severe HS who were naïve to or had failed prior anti-TNF⍺ therapy, significant clinical responses were observed in both groups with HiSCR rates of 63% in the TNF⍺-failure group and 61% in the TNF⍺-naïve group, respectively, qualifying bermekimab as potential alternative treatment option for non-responders to anti-TNF⍺ [170].

A randomized placebo and active-comparator-controlled phase IIa/b trial evaluating the efficacy of bermekimab compared to placebo and adalimumab is currently ongoing (ClinicalTrials.gov NCT04988308) [171].

Canakinumab is a human monoclonal antibody targeting IL-1β. There is limited evidence for its efficacy in HS and case reports described contradictory responses [172,173,174].

Lutikizumab, a human dual variable-domain antibody that selectively binds and inhibits IL-1⍺ and IL-1β, has been previously tested as an anti-inflammatory treatment in osteoarthritis [175,176]. A recent phase II trial studies the efficacy of lutikizumab in HS patients with failure to prior anti-TNF⍺ therapy (ClinicalTrials.gov NCT05139602) [177].

The Janus kinase and signal transducers and activators of transcription (JAK/STAT) pathway represents a rapid membrane-to-nucleus cell signaling module, which regulates the expression of various critical mediators of cancer and inflammation [178]. Inhibitors of the JAK/STAT pathway are a potential approach for future treatment of HS, as they enable the simultaneous modulation of expression of different cytokines that are involved in the complex inflammatory process of HS [141,179].

The efficacy of the JAK1 inhibitor INCB054707 was evaluated in two phase II studies (ClinicalTrials.gov NCT03569371, NCT03607487) in patients with moderate-to-severe HS. INCB054707 was well tolerated and clinical improvement of disease was observed; however, the effect was only significant in the high-dose group with 90 mg (HiSCR 88% vs. 57% placebo) [180].

Upadacitinib is a second-generation JAK inhibitor with selectivity for JAK1. In a retrospective cohort study 75% and 100% of patients treated with upadacitinib reached HiSCR after 4 and 12 weeks of treatment, respectively. HiSCR₇₅ rates were 30% and 95% after 4 weeks and 12 weeks [181]. These promising observations led to the initiation of a phase II randomized controlled trial with results unpublished (ClinicalTrials.gov NCT04430855) [182].

A phase II trial for topical treatment of early-stage HS lesions with the JAK1/JAK2 inhibitor ruxolitinib is currently ongoing (ClinicalTrials.gov NCT04414514) [60].

In acute cases with abscess formation, incision and drainage can be considered for acute pain relief, although this is only a symptom treatment with nearly 100% recurrence rates [189]. As deroofing can be performed approximately in the same amount of time, coming with higher recurrence-free rates, experts recommend deroofing over incision and drainage [41].

Deroofing describes a superficial removal of the skin covering an inflammatory nodule or a solitary sinus tract, exposing the partially epithelialized basis of the lesion with subsequently curettage of the gelatinous granulation tissue [190,191,192]. The advantages of this procedure are its simplicity, cost-effectiveness and that it can be performed under local anesthesia, qualifying this method for treatment of inflammatory nodules, abscesses and solitary sinus tracts [186]. In a small study with 44 patients undergoing deroofing of axillary or inguinal HS lesions, 87% were recurrence-free in the follow-up interval of five years [193].

The skin-tissue-sparing excision with electrosurgical peeling (STEEP) method represents a similar surgical approach and was first described by Blok et al. [194]. Here, successive tangential excisions are performed with an electrosurgical wire loop until the epithelialized bottom of the lesion is exposed, whilst saving as much healthy tissue as possible. Although this surgical technique is associated with a short time to wound healing and a low risk of wound contraction, no long-term outcomes are reported and evidence is limited on small case series [195].

Excision describes the complete removal of the affected tissue and represents a more invasive surgical approach in HS. Depending on the extent of resection experts differentiate between limited, wide and radical excisions; however, there are no generally accepted definitions and distinctions between surgical interventions are blurred [186]. Van Rappard et al. defined limited or localized excisions as the complete excision of the affected tissue, beyond the borders of activity, leaving clear margins [196]. Limited excisions represent a low-invasive surgical approach, appropriate for the treatment of recurrent inflammatory nodules or abscesses and solitary sinus tracts in Hurley stage I or II, and can be performed under local anesthesia in an outpatient setting [196]. Wide excisions are understood as the surgical removal of the affected tissue including the surrounding subcutaneous fat and perilesional skin with an additional resection margin [197,198]. In severe cases, radical excisions with the complete removal of the entire hair bearing area including the subcutaneous fat to the underlying fascia of an affected body region can be performed [20]. Nesmith et al. suggested an additional superficial lymphadenectomy for a further reduction of the risk of recurrence [199].

In cases of extensive disease with multiple or confluent sinus tracts, preoperative MRI- or ultrasound-based imaging methods or an intraoperative use of dye mapping methods, such as methyl violet or iodine starch, can contribute to an improved visualization of the surgical site [200,201,202].

Although there are no accepted definitions for surgical techniques and recurrence in HS, it is generally considered that more extensive resections are associated with a lower risk of recurrence [203].

Various laser and light-based therapies have gained increasing attention as a possible treatment modality for HS [204].

The carbon dioxide (CO₂) laser acts at a wavelength of 10,600 nm and can be used for tissue ablation in different modalities, namely vaporization and excision. CO₂-laser vaporization represents a tissue-sparing treatment option, that aims on a focal destruction of chronic or inflammatory HS lesions, and was first described by Dalrymple et al. for the treatment of sinus tracts [205]. In two case series, Lapins et al. reported low local recurrence rates and satisfactory postoperative outcomes after a stepwise horizontal CO₂-laser evaporation of sinus tracts in Hurley stage II patients [206,207]. Another retrospective study showed similar outcomes, but described local recurrence rates of 29% [208]. A retrospective study evaluated the outcomes of 185 treated sites of 61 HS patients after CO2-laser excision or marsupialization with secondary intention healing, and demonstrated fast healing rates and a local recurrence rate of 1% [209].

Summarizing, CO₂-laser interventions are tissue-sparing treatment options for HS lesions with fast postoperative wound healing and low complication rates. As they can be performed under local anesthesia and wounds are generally allowed to heal by secondary intention, these treatments seem suitable for an outpatient setting [204].

Neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers act as non-ablative lasers at a wavelength of 1064 nm and enable a selective photothermolysis of hair follicles [210]. Their efficacy has been demonstrated in several randomized controlled studies, leading to significant clinical improvements and prevention of new inflammatory lesions in the treated body areas of HS patients [211,212]. In a histopathologic study, an initially increased perifollicular inflammation, observed after 1 week of treatment, was followed by a fibrotic tissue transformation after 4–8 weeks of treatment [213]. Axillary and inguinal areas have been shown to be more responsive to Nd:YAG-laser treatment compared to inframammary and gluteal regions [212].

Moreover, combination treatments consisting of Nd:YAG-laser-mediated hair follicle destruction and CO₂-laser ablation of HS lesions have shown superior clinical responses [214,215].

There are various options for wound closure after surgical intervention, including healing by secondary intention, application of skin grafts and primary wound closure techniques [20]. Rompel et al. analyzed the outcomes of 106 HS patients undergoing radical excision and found no correlation between recurrence rates and the type of surgical reconstruction [201]. However, a current meta-analysis reported recurrence rates following wide surgical excision with 15% after primary wound closure, 8% after skin flap reconstruction and 6% after application of skin grafts, respectively [216]. Ovadja et al. described similar results with the highest recurrence rates after primary wound closure and lowest recurrence rates after skin graft coverage [217].

Negative pressure wound therapy (NPWT) has been shown to improve wound healing and wound granulation by increasing tissue oxygenation and reducing the bacterial load [218]. In HS, NPWT can be considered for postoperative wound management following wide or radical excisions. After completion of NPWT-assisted wound granulation, healing by secondary intention or defect coverage with skin grafts can be performed [219]. A small study analyzing NPWT for axillary wound management following wide excisions in HS patients reported a reduced time of hospitalization, and low recurrence and complication rates [220].

Postoperative secondary intention healing is a well established approach for wounds after surgical intervention with low recurrence rates and favorable functional outcomes [221]. However, the time to complete wound healing is generally longer than in primary wound closure options and frequent follow-up visits should be recommended to ensure optimal results [222].

Skin grafts can be considered for defect coverage following extensive excisions or in critical areas with a high risk for postoperative scar contraction. In HS split-thickness skin grafts (STSG) are the most frequently used skin grafts, as in comparison to full thickness skin grafts harvesting is easier and less invasive [223]. If required, meshing of STSG can achieve coverage of larger wound areas [224]. In a comparative study by Morgan et al. split-thickness skin grafts showed faster wound healing than healing by secondary intention. However, secondary healing with frequent wound dressing resulted in certain healing with good cosmetic results and avoided the need for immobilization and a painful donor site.

Primary wound closure represents an option for closure of small excision wounds, especially in cases with limited disease [196]. However, primary wound closure is associated with a high risk of local recurrence [216,226].

Skin flaps can be considered as a more complex reconstructive approach for wounds after larger excisions, especially when critical anatomical structures, such as nerves or blood vessels, are exposed or when there is a risk for postoperative scarring and contraction [227]. As local flaps bear the risk of containing HS affected skin, reconstruction with skin flaps should only be performed after wide surgical excisions [228]. Currently, there is a large number of different skin flaps that have been described for HS reconstruction and frequently used flaps are lateral thoracic island fasciocutaneous flaps [229], Limberg transposition flaps [230], fasciocutaneous perforator-based flaps [231], myocutaneous flaps [232,233] and thoracodorsal artery perforator flaps [234,235].