Diagnosis and Treatment of Acne Inversa/Hidradenitis Suppurativa in China:An Expert Consensus Statement(2021 Version)#

Consensus Writing Group on the Diagnosis and Treatment of Acne Inversa/Hidradenitis Suppurativa in China(Alphabetically),Hong Fang,Xing-Hua Gao,Song-Mei Geng,Heng Gu,Jun Gu,Li He,Xian Jiang,Hong-Zhong Jin,Qiang Ju,Xiao-Jing Kang0,Wei Lai,Cheng-Xin Li,Hang Li,Heng-Jin Li,Shan-Shan Li,Yu-Zhen Li,Qing Sun,Juan Tao,Baoxi Wang,*,Gang Wang0,Xin-Feng Wu,Lei-Hong Xiang,Hong-Fu Xie,Hao-Xiang Xu,Jin-Hua Xu,Yan Yan,Zhi-Zhong Zheng

1Department of Dermatology,The First Affiliated Hospital of Zhejiang University,Hangzhou,Zhejiang 310003,China,2Department of Dermatology,No.1 Hospital of China Medical University,Shenyang,Liaoning 110001,China,3Department of Dermatology,The Second Affiliated Hospital of Xi’an Jiaotong University,Xi’an,Shaanxi 710061,China,4Hospital for Skin Diseases(Institute of Dermatology),Chinese Academy of Medical Sciences and Peking Union Medical College,Nanjing,Jiangsu 210042,China,5Department of Dermatology,Shanghai Tenth People’s Hospital,Tongji University School of Medicine,Shanghai 200072,China,6Department of Dermatology,First Affiliated Hospital of Kunming Medical University,Kunming,Yunnan 650032,China,7Department of Dermatology,West China Hospital,Sichuan University,Chengdu,Sichuan 610041,China,8Department of Dermatology,Peking Union Medical College Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100021,China,9Department of Dermatology,Renji Hospital,School of Medicine,Shanghai Jiaotong University,Shanghai 200025,China,10Department of Dermatology,People’s Hospital of Xinjiang Uygur Autonomous Region,Urumqi,Xinjiang 830001,China,11Department of Dermatology and Venereology,The Third Affiliated Hospital,Sun Yat-sen University,Guangzhou,Guangdong 510630,China,12Department of Dermatology,First Medical Center of Chinese PLA General Hospital,Beijing 100853,China,13Department of Dermatology and Venerology,Peking University First Hospital,Beijing 100034,China,14Department of Dermatology,Hainan Hospital of PLA General Hospital,Sanya,Hainan 572013,China,15Department of Dermatology and Venereology,The First Hospital of Jilin University,Changchun,Jilin 130021,China,16Department of Dermatology,Second Affiliated Hospital of Harbin Medical University,Harbin,Heilongjiang 150086,China,17Department of Dermatology,Qilu Hospital of Shandong University,Jinan,Shandong 250012,China,18Department of Dermatology,Affiliated Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan,Hubei 430022,China,19Department of Dermatology,Plastic Surgery Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100144,China,20Department of Dermatology,Xijing Hospital,Fourth Military Medical University,Xi’an,Shanxi 710032,China,21Department of Plastic and Reconstructive Surgery,Institute of Dermatology,Chinese Academy of Medical Sciences,Peking Union Medical College,Nanjing,Jiangsu 210042,China,22Department of Dermatology,Huashan Hospital,Fudan University,Shanghai 200040,China,23Department of Dermatology,Xiangya Hospital,Central South University,Changsha,Hunan 410008,China.

Abstract Acne inversa/hidradenitis suppurativa is a chronic,recurrent,inflammatory skin disease that affects the pilosebaceous units,causinfollicular occlusion.The etiology and pathogenesis of acne inversa/hidradenitis suppurativa involves internal and external factors such as genetic susceptibility,inflammation and immunity,microorganisms,obesity,and smoking.acne inversa/hidradenitis suppurativa is difficult to treat,and the current aim of treatment is to control the frequency and duration of disease flares and improve the quality of life.Treatment protocols for acne inversa/hidradenitis suppurativa should be selected based on the disease severity grade.Medical treatments include antibiotics,retinoids,biologics,immunosuppressive agents,and antiandrogen agents.Adjuvant treatments include surgery and laser/light therapies.This consensus aims to further standardize the diagnosis and treatment procedures of acne inversa/hidradenitis suppurativa in China to facilitate its diagnosis and treatment.

Keywords:acne inversa,consensus,diagnosis,hidradenitis suppurativa,therapy

Introduction

Acne inversa(AI)/hidradenitis suppurativa(HS)is a chronic,recurrent,inflammatory skin disease that affects the pilosebaceous units,causing follicular occlusion.AI/HS lesions occur in the apocrine gland-bearing areas of the body,most commonly the axillae,inguinal,and anogenital regions.The manifestations of AI/HS are painful,deepseated,inflammatory nodules that first develop during puberty,resulting in abscesses,sinus tracts,and scars that have a profound negative impact on patients’quality of life.The prevalence of AI/HS reportedly varies from 0.05% to 4.1% in Europe and America,1-3with women more frequently affected than men(ratio 3:1).1-2Furthermore,30%-40% of patients with AI/HS have a family history.4-5The reported prevalence of AI/HS in Asia is 0.04%-0.06%,with men more frequently affected than women(ratio 1.6-2.5:1).6-8However,to date,there are no epidemiological data for AI/HS in China.To facilitate the standardization of AI/HS diagnosis and treatment in China,we formulated this AI/HS consensus based on evidence-based medicine and up-to-date research to provide a reference for clinicians.

Etiology and pathogenesis

The etiology and pathogenesis of AI/HS are not fully understood.However,the factors associated with the development and exacerbation of AI/HS include genetic susceptibility,immunity,inflammation,variations in the skin microbiome,obesity,and smoking.These factors may cause follicular hyperkeratosis,follicular plugging,and follicular content retention,resulting in follicular duct rupture,leakage of follicular contents,and secondary inflammation.Recurrence causes destruction of the tissue structure and scarring.

Genetics

The genetic factors involved in familial AI/HS are mutations of three subunits of gamma-secretase(presenilin,presenilin enhancer-2,and nicastrin).9Gammasecretase not only plays an important role in the innate immune system,but also participates in the maturation and differentiation of the follicular epithelium.Loss-offunction mutation of gamma-secretase causes the impairment of Notch signaling,which contributes to the pathogenesis of AI/HS.10Abnormal gamma-secretase also causes dysfunction of epidermal growth factor receptors,resulting in epithelial keratinocyte hyperplasia and follicular hyperkeratosis,which are associated with the development of AI/HS.11This gene mutation of gammasecretase is not found in patients with sporadic AI/HS without a family history of the disease,although the same histopathologic findings and clinical manifestations are seen in patients with AI/HS with or without a family history.

Immunity and inflammation

Follicular occlusion,infiltration of inflammatory cells around the follicle,and an abnormal innate immune response in the folliculopilosebaceous units appear to be important events in the development of AI/HS.AI/HS lesions show enhanced expression of inflammatory cytokines such as tumor necrosis factor(TNF)-α,interleukin(IL)-17,and inflammatory cytokines associated with activated caspase-1(including IL-1βand IL-18),12and clustering of T helper 1/T helper 17-associated cytokines(interferon-γ,IL-12,IL-23,and IL-32).13-14In contrast,Th2-associated cytokines such as IL-13 are inversely correlated with the presence of TH1/TH17-associated cytokines.14Keratinocytes isolated from the hair follicles of patients with AI/HS secrete significantly more chemokines(such as chemokine ligand(CCL)-5,CCL-20,and CCL-27)and cytokines(such as TNF-α,IL-1β,IL-6,and IL-10)after stimulation.15These findings suggest that the innate immune response contributes to the inflammation seen in AI/HS.16-17In addition,recent studies indicate that patients with AI/HS have significantly increased serum concentrations of circulating complement C5a and C5b-9,which stimulate peripheral blood mononuclear cells to produce excessive TNF-α,and that this process is reversed by the addition of complement C5a monoclonal antibody(mAb).18-19

Skin microbiome

The skin microbiome in AI/HS lesional skin mainly consists of Corynebacterium,Porphyromonas,and Peptoniphilus species.Conversely,AI/HS lesions have significantly decreased amounts of Propionibacterium acnes compared with healthy controls.The various microbiome types of non-lesional areas are more equally distributed than that of lesional areas.20The skin microbiome may participate in secondary infection and the inflammatory process of AI/HS.Biofilms are detected in 67%of chronic AI/HS lesions and in 75%of perilesional skin regions;this structure serves as a protective layer against host defense mechanisms and antimicrobial agents,causing the circumvention of host immune-mediated clearance,which leads to persistent infections.21-23

Other factors

Obesity and smoking are risk factors for AI/HS.Increased mechanical stress on intertriginous skin,sweat retention,and increased secretion of inflammatory cytokines may be involved in the pathogenesis of AI/HS in patients with obesity.24Nicotine and benzopyrene may contribute to the development of epidermal hyperplasia,follicular plugs,and inflammation.25

Clinical manifestations

Typical AI/HS lesions include open comedones(characteristically paired),inflammatory papules,nodules,cysts,abscesses,sinus tracts,and fistulae.Skin contracture and scar formation are seen in the late stage of the disease.Some patients with AI/HS may have pilonidal sinuses.Recurrent lesions can cause severe pain.Sinuses and hypertrophic scar formation may appear in patients with a long course of disease or recurrence.AI/HS can be accompanied by or secondary to a variety of systemic diseases such as diabetes,lymphedema,anemia,hypoproteinemia,and autoinflammatory disease(particularly inflammatory bowel disease,inflammatory arthritis,synovitis,acne,pustulosis,hyperostosis,osteitis syndrome,and pyoderma gangrenosum),depression,and anxiety.Chronic ulcers can secondarily develop into squamous cell carcinoma.

AI/HScanbedividedintothefollowingsubtypesbasedon clinical phenotypes:regular,frictional furuncle,scarring folliculitis,acne conglobata,syndromic,and ectopic.26-27The characteristics of each subtype are listed in Table 1.HS may present as a componentof thefollicular occlusiontriad,accompanying acne conglobata and dissecting cellulitis of the scalp.When the follicular occlusion triad is accompanied by the development of a pilonidal sinus,it is referred to as the follicular occlusion tetrad.

Diagnosis

Diagnostic criteria

At present,there are no unified diagnostic criteria for AI/HS in China.Based on the guidelines formulated by the European Academy of Dermatology and Venerology and the United States and Canadian Hidradenitis Suppurativa Foundations,28-29our consensus proposes the following diagnostic criteria.(1)History:recurrent painful or suppurating lesions.(2)Typical clinical manifestations:deep-seated painful nodules,abscesses,sinus tracts,and scarring in the axillae,genitofemoral area,perineal and gluteal areas,and infra-mammary area of women.(3)Family history of AI/HS.(4)Histopathology of lesions:follicular hyperkeratosis,follicular plugging,and lymphocytic perifolliculitis in the early stage;dense mixed inflammatory infiltrate involving the lower half of the dermis and subcutis in the acute stage(chronic abscesses,open sinus tracts filled with inflammatory cells and keratin,granulation tissue with inflammatory cells and foreign body giant cells may also be present);destruction of the folliculopilosebaceous units with extensive fibrosis in the chronic stage.Patients who satisfy the first two criteria are diagnosed with AI/HS.Patients who satisfy the third criteria are considered to have familial AI/HS.The fourth criterion is helpful in differentiating the disease from similar conditions.

Differential diagnoses

When AI/HS lesions present as comedones,papules,nodules,and cysts,the condition must be differentiatedfrom acne vulgaris,furuncles,carbuncles,erysipelas,cellulitis,and dermoid cysts.AI/HS presenting as abscesses,sinus tracts,and fistulae must be differentiated from actinomycosis,nocardiosis,ulcerative cutaneous tuberculosis,granuloma inguinale,cutaneous Crohn disease,perirectal abscess,anal fistula,and ischiorectal abscess.Clinicians must take care to exclude cutaneous squamous cell carcinoma in patients with AI/HS presenting as chronic ulcers.The typical location and distribution of lesions combined with the histopathologic appearance enable the differentiation of AI/HS from other diseases.

Table 1 Clinical subtypes and characteristics of acne inversa/hidradenitis suppurativa(HS).

Classification and severity assessment

Hurley staging

Hurley proposed the following AI/HS severity classification in 1989.30Stage I:formation of single or multiple abscess without sinus tracts and cicatrization/scarring.Stage II:recurrent abscesses with sinus tracts and scarring,single or multiple widely separated lesions.Stage III:diffuse or almost diffuse involvement,or multiple interconnected sinus tracts and abscesses across the entire area.The Hurley classification is simple to use and is,therefore,widely applied,especially in the clinical setting and in epidemiologic investigations.However,this classification is not quantitative,and is based on static findings of the disease such as scarring and fistulas.Therefore,it is not sensitive enough to monitor the efficacy of interventions in clinical trials.

Sartorius score

The Sartorius score was created by Sartorius et al.31in 2003 and modified in 2009.32The modified Sartorius score is based on the number of individual nodules and fistulas in each patient,and is suitable for the dynamic measurement of the clinical severity of AI/HS.However,this scoring system is limited in severe cases in which separate lesions aggregate into confluent plaques,which may be resistant to medical treatments.

To increase the sensitivity of the assessment of the treatment response,Hessam et al.33created the Severity Assessment of Hidradenitis Suppurativa score based on the Hurley staging and modified Sartorius score;other scores such as the Hidradenitis Suppurativa Severity Index,34-35hidradenitis suppurativa clinical response,36and International Hidradenitis Suppurativa Severity Score System(IHS4)37were subsequently established.Because the IHS4 includes assessments of the numbers of nodules,abscesses,and fistulae,which indicate the disease activity,it provides a more sensitive evaluation of the effectiveness of medical intervention.The IHS4 is calculated as the number of nodules multiplied by 1+the number of abscesses multiplied by 2+the number of fistulae multiplied by 4.An IHS4 score of 3 or less signifies mild HS,a score of 4-10 signifies moderate HS,and a score of 11 or higher signifies severe HS.Some subjective evaluation indexes are also used to evaluate AI/HS,such as the Physician Global Assessment,38visual analog scale,and Dermatology Life Quality Index;these scores can be used alone or in combination to assess the severity and treatment response of AI/HS.

At present,Hurley staging is widely used internationally to grade the treatment of AI/HS,while the Sartorius score is much more commonly described in studies to enable readers to understand the clinical features of the disease.However,both scoring systems have limitations.Although the usefulness of the IHS4 in the assessment of the treatment response requires further confirmation,our consensus recommends the use of the IHS4 in clinical practice.

Treatment

The Hurley staging is used to classify the severity of AI/HS as mild,moderate,and severe.Different therapeutic regimes should be considered based on the severity of the disease.

Topical and intralesional therapies

Topical treatments are mainly used in mild cases of AI/HS,or as an adjuvant treatment for moderate and severe cases.28,39-46Topical clindamycin 1% solution may reduce bacterial colonization and inflammatory reactions,and is used to treat inflammatory lesions such as papules and pustules.The proposed dosing regimen is twice daily for 12 weeks.28,44However,there is a risk of bacterial resistance.Alternative options include antibiotic agents such as chlorhexidine,40benzoyl peroxide,40and ichthyol.Topical exfoliants such as retinoic acids and resorcinol 15% cream28,40,42,44,46may improve follicular keratosis and reduce follicular obstruction.Intralesional corticosteroid injection(such as 0.2-2mL of 5-10mg/mL triamcinolone acetonide)is advocated for the rapid reduction of inflammation and pain associated with acute flares28,42,46and to manage recalcitrant nodules and sinus tracts.However,glucocorticoids should be used with caution in cases with a positive bacterial culture of a sinus tract.

Systemic therapies Antibiotics

Systemic antibiotics are recommended for patients with obvious infectious inflammation.

First-line therapy

Oral tetracyclines28,39-46are recommended for mild and moderate AI/HS.The proposed dosing regimens include 500mg of tetracycline twice daily,100mg of doxycycline twice daily,or 50-100mg of minocycline twice daily for 12weeks.Tetracyclines are contraindicated in children younger than 8years,and in pregnant and lactating women.

Second-line therapy

Combination clindamycin and rifampin therapy28,39-46is an option in mild or moderate cases that fail to respond to first-line therapy.The recommended regimen is 300mg of clindamycin twice daily combined with 300mg of rifampin twice daily or 600mg of rifampin once daily for 10-12 weeks.Caution is needed,as rifampin is a strong inducer of cytochrome P450 and may interfere with the metabolism and toxicity of other drugs metabolized by the same pathway.

Third-line therapy

A triple regimen of rifampicin-moxifloxacin-metronidazole may be a viable alternative in severe cases.28,40,41The recommended regimen is 500mg of metronidazole three times daily,400mg of moxifloxacin once daily,and 300 mg of rifampicin twice daily or 10 mg·kg-1·d-1for 12 weeks,with metronidazole discontinuation after 6weeks.For patients with AI/HS that does not respond to antibiotic treatments,those with concomitant systemic inflammatory response syndrome,or those with a positive blood bacterial culture,clinicians should consider using ertapenem or other antibiotics based on susceptibility tests.The dosage of ertapenem is 1g once daily by intravenous infusion.40,41,47Furthermore,ertapenem can be used as a rescue therapy in severe cases and as an effective bridging therapy to surgery and other maintenance regimens.The course and frequency of antibiotics should be balanced against the risks of bacterial resistance.

Retinoids

The mechanisms of retinoids include the reduction of hyperkeratosis of the hair follicles and sebaceous ducts(decreasing the formation of horny plugs in the hair follicles),reduction of inflammation,and improvement of scars.However,there is a lack of valid evidence for the efficacy of retinoids in AI/HS.Oral acitretin is suggested for the treatment of early or chronic AI/HS in patients who are refractory to oral or topical antibiotic treatments.28,39-46The recommended dose is 0.20-0.88 mg·kg-1·d-1for 3-12months.However,retinoids are teratogenic and must be avoided in women of childbearing age.Isotretinoin is only recommended for patients with AI/HS with moderate or severe acne or who fail to respond to conventional therapies.

Biologics

In recent years,various biologic agents have emerged as a robust treatment option for autoimmune inflammatory disease.Biologic agents targeting different signaling molecules in AI/HS include TNF-αantagonists(adalimumab,infliximab,and etanercept),IL-1 antagonists(anakinra and canakinumab),IL-12/23 antagonists(ustekinumab),IL-17A antagonists(secukinumab),phosphodiesterase 4 inhibitor(apremilast),and complement 5a inhibitors(IFX-1)as potential therapies.Some of these agents have been used in the clinical setting,while others are still at the clinical trial stage.19,48No biological agent or small molecule drug has yet been approved by the State Drug Administration for AI/HS treatment in China.Biologics are used internationally in patients with moderate and severe AI/HS who fail to respond to systemic antibiotics.28,39-46In China,however,the indications of biologics in HS must be carefully considered.Clear communication with the patient and the attainment of informed consent are necessary before commencing treatment with biologics.Patients must be carefully monitored for adverse reactions,such as secondary infection(eg,upper respiratory infection),cardiovascular events,and signs of neoplasia during treatment.

Adalimumab is a recombinant fully human mAb,and is the only biologic agent that has been approved by the US Food and Drug Administration for the treatment of HS.49The proposed dosing regimens are:(1)160mg of subcutaneous adalimumab at week 0,80mg at week 2,and then 40mg weekly from week 4 for 12weeks,(2)40 mg subcutaneous weekly for 12 weeks.28,44-46

Infliximab is a chimeric mAb against TNF and is the second-line biological agent for AI/HS treatment.28,39-44,46The proposed dosing regimen is 5mg/kg body weight intravenously on weeks 0,2,and 6,and then every 8weeks for 12weeks.

Ustekinumab is an IL-12/23 mAb that has proved effective for AI/HS in small sample-sized clinical trials.The reference dose is 45mg subcutaneously for patients weighing≤100kg or 90mg subcutaneously for those weighing＞100kg on weeks 0 and 4,and then every 12 weeks for 40 weeks.28,40,46

Corticosteroids and immunosuppressants

Short-term,rapidly tapering glucocorticoid therapy is an option for the management of acute AI/HS flares or as an induction therapy with other systemic treatments.28,40-46The proposed initial dosing regimen is a 0.5-0.7 mg·kg-1·d-1equivalent dose of prednisone orally,with the dose tapered when the disease is under control.Immunosuppressants inhibit the inflammatory cascades of AI/HS and are considered third-line therapy for patients who fail to respond to standard treatments.Ciclosporin A is a calcineurin inhibitor specifically targeting T lymphocytes with potent immunosuppressive activity,and is an option for long-term control of inflammation.28,44-46The reference dose of Ciclosporin A is 2-5 mg·kg-1·d-1for 6 weeks to 7months.Patients must be carefully monitored for adverse effects such as nephrotoxicity,neurotoxicity,and hypertension.

Other drugs

Antiandrogenic agents

Antiandrogens reduce sebaceous gland secretions and improve the keratinization of hair follicles by antagonizing androgenic activities.Antiandrogens are indicated for female patients with AI/HS with one or more of the following conditions28,40,44,46:(1)AI/HS flares in association with menses,(2)acneiform manifestations,(3)diabetes,polycystic ovarian syndrome,or hyperandrogenic syndrome.Cyproterone acetate combined with ethinylestradiol has antiandrogenic effects and can be used as monotherapy in females with mild-to-moderate AI/HS or as adjunctive agents in female patients with more severe disease.

Metformin

Metformin improves insulin resistance and reduces the production of insulin-like growth factor-1 and androgen.It is applied to treat AI/HS in female patients with diabetes or polycystic ovarian syndrome.40,44-46The proposed dosing regimen is 500mg orally 2-3 times daily.

Dapsone

Dapsone is another therapy option for patients with mild to moderate AI/HS.28,44-46Efficacy is reported at a dose of 25-200mg per day.Patients must be carefully monitored for hematologic toxicity during treatment.Dapsone should be avoided in patients with glucose-6-phosphate dehydrogenase deficiency,in whom dapsone may cause severe hemolysis.Testing for the HLA-B*13:01 allelic gene helps to avoid the development of dapsone syndrome.

Zinc

Zinc has some anti-inflammatory properties and inhibits the chemotaxis of neutrophils and the expression of Tolllike receptor 2 in keratinocytes.50Oral zinc gluconate can be used as second-line therapy for mild to moderate AI/HS,or as an adjuvant agent with topical or systemic antibiotics.The proposed dosing regimen is 90mg once daily.It should be noted that zinc may reduce copper and iron absorption.

Colchicine

Colchicine inhibits the chemotaxis of neutrophils and can be considered as monotherapy in maintenance treatment or as an adjuvant agent in combination with antibiotic therapy.The dose is 0.5mg twice daily for 6-9months.Patients should be monitored for possible gastrointestinal reactions,muscle and peripheral neuropathic changes,and myelosuppression.

Thalidomide

As an immunomodulator,thalidomide inhibits the production of inflammatory cytokines and may be used in the treatment of AI/HS.The reference dose is 50-100mg per day for over 4 months.51Clinicians must be aware that thalidomide causes teratogenic effects and other adverse reactions.

Physical therapy

Laser therapy,photodynamic therapy,intense pulsed light,and radiofrequency therapies are used as adjuvant or supplementary treatments for AI/HS.28-29,43-44,52-53Carbon dioxide laser vaporizes nodules,abscesses,and fistulas and can be applied for the excision of affected skin,decompression,and scar repair in patients with moderate and severe AI/HS.A long-pulsed 1064nm neodymium:yttrium-aluminium-garnet laser has a selective photothermal effect on hair follicles and can be used to remove inflammatory lesions and reduce recurrence54in patients with moderate and severe AI/HS.Photodynamic therapy involves the combined use of a photosensitizer and a light source to induce cellular destruction through porphyrin activation,which improves the keratinization of hair follicle sebaceous ducts and has antibacterial and antiinflammatory effects;clinical reports show that this therapy is effective in the treatment of AI/HS.28,55

Surgical therapy

Incision and drainage relieve the pain associated with acute AI/HS flares.40-41,46Deroofing surgery is effective for recurrent nodules and sinuses,and is suitable for mild scattered lesions or widely distributed moderate to severe lesions.28-29,41,44-46For patients with refractory and severe disease,wide excision can be beneficial.Before excision,it is necessary to examine and assess the range and depth of AI/HS involvement to determine whether important tissues and organs such as the anal canal are involved.During surgery,appropriate anesthesia should be applied in accordance with the lesion locations.In most cases,improved expansion anesthesia technology meets the requirement of surgery.The injection of methylene blue into the sinus assists in sinus tract identification.56After the complete excision of all sinuses and involved soft tissues,reconstruction surgery should be performed in accordance with the size and location of the excised area.The most common method used to repair such defects is split-thickness skin grafting.

Pain management

There are no specific treatments for the pain caused by AI/HS due to the lack of studies on the mechanism of AI/HS pain.Topical analgesics such as 5% lidocaine gel,diclofenac gel,and nonsteroidal anti-inflammatory drugs can be used.In refractory cases,neurotic analgesics(gabapentin,pregabalin),tramadol,and opioids can be considered as alternatives.28-29,43,57Controlling the inflammation of AI/HS as soon as possible is beneficial in relieving the pain.

Combination and grading treatment

The aims of AI/HS treatment are to reduce the frequency and duration of recurrence,relieve inflammation,and improve patients’quality of life.It is difficult to completely control the symptoms of AI/HS with monotherapy;therefore,combination therapies are necessary in most cases.Treatment methods should be selected in accordance with the severity of the disease.The recommended grading of treatments in this consensus is shown in Table 2.Traditional Chinese medicine treatment for AI/HS will be formulated separately.

Table 2

Patient education and management

As AI/HS is a complex psychosomatic disorder,psychological counseling and follow-up,reasonable and standard treatment,and patient education are crucial to ensure the efficacy of treatment.

Health education

Smoking cessation,weight loss,and avoidance of friction caused by tight clothing help prevent the recurrence of AI/HS.

Psychological counseling

AI/HS causes continued pain,malodorous odors,and scar formation,all of which negatively affect patients’social activity and daily life.Therefore,patients commonly experience anxiety and depression related to AI/HS,and it is important to provide professional psychological counseling and behavioral intervention to relieve their anxiety and help them build confidence.

Regular follow-up

AI/HS is a chronic recurrent disease that requires longterm medical care.Regular follow-up is essential to enable the timely adjustment of the therapeutic regimen in accordance with the severity of skin lesions and treatment response to control the frequency of flares,reduce the incidences of sequelae,and improve patients’quality of life.