Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate®

Hidradenitis suppurativa (acne inversa): Pathogenesis, clinical features, and diagnosis

John R Ingram, MD, PhD
Section Editors
Robert P Dellavalle, MD, PhD, MSPH
Mark V Dahl, MD
Deputy Editor
Abena O Ofori, MD


Hidradenitis suppurativa (HS, from the Greek hidros = sweat and aden = glands) is a chronic inflammatory skin condition that is also known as acne inversa (AI), and historically, as Verneuil's disease [1,2]. Although the name "hidradenitis suppurativa" implies a suppurative disorder that primarily involves sweat glands, increasing knowledge of the pathogenesis of the condition has led to the prevailing theory that HS/AI is a chronic follicular occlusive disease involving the follicular portion of folliculopilosebaceous units (FPSUs).

The primary sites of involvement for HS/AI are the intertriginous skin areas of the axillary, groin, perianal, perineal, and inframammary regions, though HS/AI can occur in any skin area that contains FPSUs. The clinical manifestations vary, ranging from recurrent inflamed nodules and abscesses to draining sinus tracts and bands of severe scar formation. The associated pain, malodor, drainage, and disfigurement that accompany HS/AI contribute to a profound psychosocial impact of the disease on many patients [3].

Early HS/AI lesions often mimic other disorders; misdiagnosis of HS/AI as recurrent furunculosis or "boils" is common. Prompt recognition of the correct diagnosis is important. An early and accurate diagnosis facilitates the initiation of a treatment plan aimed at minimizing the risk of progression to disabling, end-stage disease.

The pathogenesis, clinical manifestations, and diagnosis of HS/AI will be discussed here. Treatment is reviewed separately. (See "Hidradenitis suppurativa (acne inversa): Treatment".)


Estimates of the prevalence of hidradenitis suppurativa (acne inversa, HS/AI) have varied, ranging from less than 1 percent to 4 percent [4-8]. The first population-based incidence study of HS/AI found an annual age- and sex-adjusted incidence of 6 per 100,000 in a county in Minnesota [9]. A subsequent, larger, population-based study that utilized data from a database of more than 48 million patients in the United States found a higher incidence (11.4 per 100,000 population) [10].


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Jul 2017. | This topic last updated: Aug 10, 2017.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.
  1. Sellheyer K, Krahl D. "Hidradenitis suppurativa" is acne inversa! An appeal to (finally) abandon a misnomer. Int J Dermatol 2005; 44:535.
  2. Bazex J, Bayle P, San B. Hidradenitis suppurativa is acne inversa. Int J Dermatol 2007; 46:330; author reply 330.
  3. Kouris A, Platsidaki E, Christodoulou C, et al. Quality of Life and Psychosocial Implications in Patients with Hidradenitis Suppurativa. Dermatology 2016; 232:687.
  4. Alikhan A, Lynch PJ, Eisen DB. Hidradenitis suppurativa: a comprehensive review. J Am Acad Dermatol 2009; 60:539.
  5. Jemec GB. Clinical practice. Hidradenitis suppurativa. N Engl J Med 2012; 366:158.
  6. Cosmatos I, Matcho A, Weinstein R, et al. Analysis of patient claims data to determine the prevalence of hidradenitis suppurativa in the United States. J Am Acad Dermatol 2013; 68:412.
  7. McMillan K. Hidradenitis suppurativa: number of diagnosed patients, demographic characteristics, and treatment patterns in the United States. Am J Epidemiol 2014; 179:1477.
  8. Garg A, Kirby JS, Lavian J, et al. Sex- and Age-Adjusted Population Analysis of Prevalence Estimates for Hidradenitis Suppurativa in the United States. JAMA Dermatol 2017; 153:760.
  9. Vazquez BG, Alikhan A, Weaver AL, et al. Incidence of hidradenitis suppurativa and associated factors: a population-based study of Olmsted County, Minnesota. J Invest Dermatol 2013; 133:97.
  10. Garg A, Lavian J, Lin G, et al. Incidence of hidradenitis suppurativa in the United States: A sex- and age-adjusted population analysis. J Am Acad Dermatol 2017; 77:118.
  11. Canoui-Poitrine F, Le Thuaut A, Revuz JE, et al. Identification of three hidradenitis suppurativa phenotypes: latent class analysis of a cross-sectional study. J Invest Dermatol 2013; 133:1506.
  12. van der Zee HH, Laman JD, Boer J, Prens EP. Hidradenitis suppurativa: viewpoint on clinical phenotyping, pathogenesis and novel treatments. Exp Dermatol 2012; 21:735.
  13. von Laffert M, Stadie V, Wohlrab J, Marsch WC. Hidradenitis suppurativa/acne inversa: bilocated epithelial hyperplasia with very different sequelae. Br J Dermatol 2011; 164:367.
  14. Hana A, Booken D, Henrich C, et al. Functional significance of non-neuronal acetylcholine in skin epithelia. Life Sci 2007; 80:2214.
  15. Melnik BC, Plewig G. Impaired Notch signalling: the unifying mechanism explaining the pathogenesis of hidradenitis suppurativa (acne inversa). Br J Dermatol 2013; 168:876.
  16. Kurokawa I, Danby FW, Ju Q, et al. New developments in our understanding of acne pathogenesis and treatment. Exp Dermatol 2009; 18:821.
  17. Nazary M, van der Zee HH, Prens EP, et al. Pathogenesis and pharmacotherapy of Hidradenitis suppurativa. Eur J Pharmacol 2011; 672:1.
  18. von Laffert M, Helmbold P, Wohlrab J, et al. Hidradenitis suppurativa (acne inversa): early inflammatory events at terminal follicles and at interfollicular epidermis. Exp Dermatol 2010; 19:533.
  19. Danby FW, Jemec GB, Marsch WCh, von Laffert M. Preliminary findings suggest hidradenitis suppurativa may be due to defective follicular support. Br J Dermatol 2013; 168:1034.
  20. Gniadecki R, Jemec GB. Lipid raft-enriched stem cell-like keratinocytes in the epidermis, hair follicles and sinus tracts in hidradenitis suppurativa. Exp Dermatol 2004; 13:361.
  21. Kurzen H, Kurokawa I, Jemec GB, et al. What causes hidradenitis suppurativa? Exp Dermatol 2008; 17:455.
  22. Egeberg A, Jemec GBE, Kimball AB, et al. Prevalence and Risk of Inflammatory Bowel Disease in Patients with Hidradenitis Suppurativa. J Invest Dermatol 2017; 137:1060.
  23. Deckers IE, Benhadou F, Koldijk MJ, et al. Inflammatory bowel disease is associated with hidradenitis suppurativa: Results from a multicenter cross-sectional study. J Am Acad Dermatol 2017; 76:49.
  24. Roussomoustakaki M, Dimoulios P, Chatzicostas C, et al. Hidradenitis suppurativa associated with Crohn's disease and spondyloarthropathy: response to anti-TNF therapy. J Gastroenterol 2003; 38:1000.
  25. van der Zee HH, van der Woude CJ, Florencia EF, Prens EP. Hidradenitis suppurativa and inflammatory bowel disease: are they associated? Results of a pilot study. Br J Dermatol 2010; 162:195.
  26. Giamarellos-Bourboulis EJ, Antonopoulou A, Petropoulou C, et al. Altered innate and adaptive immune responses in patients with hidradenitis suppurativa. Br J Dermatol 2007; 156:51.
  27. Kelly G, Hughes R, McGarry T, et al. Dysregulated cytokine expression in lesional and nonlesional skin in hidradenitis suppurativa. Br J Dermatol 2015; 173:1431.
  28. von der Werth JM, Williams HC. The natural history of hidradenitis suppurativa. J Eur Acad Dermatol Venereol 2000; 14:389.
  29. Deckers IE, van der Zee HH, Boer J, Prens EP. Correlation of early-onset hidradenitis suppurativa with stronger genetic susceptibility and more widespread involvement. J Am Acad Dermatol 2015; 72:485.
  30. Gao M, Wang PG, Cui Y, et al. Inversa acne (hidradenitis suppurativa): a case report and identification of the locus at chromosome 1p21.1-1q25.3. J Invest Dermatol 2006; 126:1302.
  31. Al-Ali FM, Ratnamala U, Mehta TY, et al. Hidradenitis suppurativa (or Acne inversa) with autosomal dominant inheritance is not linked to chromosome 1p21.1-1q25.3 region. Exp Dermatol 2010; 19:851.
  32. Pink AE, Simpson MA, Desai N, et al. Mutations in the γ-secretase genes NCSTN, PSENEN, and PSEN1 underlie rare forms of hidradenitis suppurativa (acne inversa). J Invest Dermatol 2012; 132:2459.
  33. Pink AE, Simpson MA, Desai N, et al. γ-Secretase mutations in hidradenitis suppurativa: new insights into disease pathogenesis. J Invest Dermatol 2013; 133:601.
  34. Ingram JR. The Genetics of Hidradenitis Suppurativa. Dermatol Clin 2016; 34:23.
  35. Melnik BC, Plewig G. Impaired Notch-MKP-1 signalling in hidradenitis suppurativa: an approach to pathogenesis by evidence from translational biology. Exp Dermatol 2013; 22:172.
  36. Li CR, Jiang MJ, Shen DB, et al. Two novel mutations of the nicastrin gene in Chinese patients with acne inversa. Br J Dermatol 2011; 165:415.
  37. Jiao T, Dong H, Jin L, et al. A novel nicastrin mutation in a large Chinese family with hidradenitis suppurativa. Br J Dermatol 2013; 168:1141.
  38. Chen S, Mattei P, You J, et al. γ-Secretase Mutation in an African American Family With Hidradenitis Suppurativa. JAMA Dermatol 2015; 151:668.
  39. Xu H, Xiao X, Hui Y, et al. Phenotype of 53 Chinese individuals with nicastrin gene mutations in association with familial hidradenitis suppurativa (acne inversa). Br J Dermatol 2016; 174:927.
  40. Savva A, Kanni T, Damoraki G, et al. Impact of Toll-like receptor-4 and tumour necrosis factor gene polymorphisms in patients with hidradenitis suppurativa. Br J Dermatol 2013; 168:311.
  41. Revuz JE, Canoui-Poitrine F, Wolkenstein P, et al. Prevalence and factors associated with hidradenitis suppurativa: results from two case-control studies. J Am Acad Dermatol 2008; 59:596.
  42. Danby FW. Diet in the prevention of hidradenitis suppurativa (acne inversa). J Am Acad Dermatol 2015; 73:S52.
  43. Sartorius K, Emtestam L, Jemec GB, Lapins J. Objective scoring of hidradenitis suppurativa reflecting the role of tobacco smoking and obesity. Br J Dermatol 2009; 161:831.
  44. Canoui-Poitrine F, Revuz JE, Wolkenstein P, et al. Clinical characteristics of a series of 302 French patients with hidradenitis suppurativa, with an analysis of factors associated with disease severity. J Am Acad Dermatol 2009; 61:51.
  45. Crowley JJ, Mekkes JR, Zouboulis CC, et al. Association of hidradenitis suppurativa disease severity with increased risk for systemic comorbidities. Br J Dermatol 2014; 171:1561.
  46. Schrader AM, Deckers IE, van der Zee HH, et al. Hidradenitis suppurativa: a retrospective study of 846 Dutch patients to identify factors associated with disease severity. J Am Acad Dermatol 2014; 71:460.
  47. Shalom G, Freud T, Harman-Boehm I, et al. Hidradenitis suppurativa and metabolic syndrome: a comparative cross-sectional study of 3207 patients. Br J Dermatol 2015; 173:464.
  48. Bettoli V, Naldi L, Cazzaniga S, et al. Overweight, diabetes and disease duration influence clinical severity in hidradenitis suppurativa-acne inversa: evidence from the national Italian registry. Br J Dermatol 2016; 174:195.
  49. Melnik BC, Zouboulis CC. Potential role of FoxO1 and mTORC1 in the pathogenesis of Western diet-induced acne. Exp Dermatol 2013; 22:311.
  50. Attanoos RL, Appleton MA, Douglas-Jones AG. The pathogenesis of hidradenitis suppurativa: a closer look at apocrine and apoeccrine glands. Br J Dermatol 1995; 133:254.
  51. König A, Lehmann C, Rompel R, Happle R. Cigarette smoking as a triggering factor of hidradenitis suppurativa. Dermatology 1999; 198:261.
  52. Mortaz E, Adcock IM, Ito K, et al. Cigarette smoke induces CXCL8 production by human neutrophils via activation of TLR9 receptor. Eur Respir J 2010; 36:1143.
  53. Joseph MA, Jayaseelan E, Ganapathi B, Stephen J. Hidradenitis suppurativa treated with finasteride. J Dermatolog Treat 2005; 16:75.
  54. Randhawa HK, Hamilton J, Pope E. Finasteride for the treatment of hidradenitis suppurativa in children and adolescents. JAMA Dermatol 2013; 149:732.
  55. Kraft JN, Searles GE. Hidradenitis suppurativa in 64 female patients: retrospective study comparing oral antibiotics and antiandrogen therapy. J Cutan Med Surg 2007; 11:125.
  56. Mortimer PS, Dawber RP, Gales MA, Moore RA. A double-blind controlled cross-over trial of cyproterone acetate in females with hidradenitis suppurativa. Br J Dermatol 1986; 115:263.
  57. Vossen AR, van Straalen KR, Prens EP, van der Zee HH. Menses and pregnancy affect symptoms in hidradenitis suppurativa: A cross-sectional study. J Am Acad Dermatol 2017; 76:155.
  58. Barth JH, Layton AM, Cunliffe WJ. Endocrine factors in pre- and postmenopausal women with hidradenitis suppurativa. Br J Dermatol 1996; 134:1057.
  59. Lapins J, Jarstrand C, Emtestam L. Coagulase-negative staphylococci are the most common bacteria found in cultures from the deep portions of hidradenitis suppurativa lesions, as obtained by carbon dioxide laser surgery. Br J Dermatol 1999; 140:90.
  60. Sartorius K, Killasli H, Oprica C, et al. Bacteriology of hidradenitis suppurativa exacerbations and deep tissue cultures obtained during carbon dioxide laser treatment. Br J Dermatol 2012; 166:879.
  61. Kathju S, Lasko LA, Stoodley P. Considering hidradenitis suppurativa as a bacterial biofilm disease. FEMS Immunol Med Microbiol 2012; 65:385.
  62. Ring HC, Bay L, Nilsson M, et al. Bacterial biofilm in chronic lesions of hidradenitis suppurativa. Br J Dermatol 2017; 176:993.
  63. Ring HC, Thorsen J, Saunte DM, et al. The Follicular Skin Microbiome in Patients With Hidradenitis Suppurativa and Healthy Controls. JAMA Dermatol 2017.
  64. Stellon AJ, Wakeling M. Hidradenitis suppurativa associated with use of oral contraceptives. BMJ 1989; 298:28.
  65. Gupta AK, Knowles SR, Gupta MA, et al. Lithium therapy associated with hidradenitis suppurativa: case report and a review of the dermatologic side effects of lithium. J Am Acad Dermatol 1995; 32:382.
  66. Aithal V, Appaih P. Lithium induced hidradenitis suppurativa and acne conglobata. Indian J Dermatol Venereol Leprol 2004; 70:307.
  67. Faivre C, Villani AP, Aubin F, et al. Hidradenitis suppurativa (HS): An unrecognized paradoxical effect of biologic agents (BA) used in chronic inflammatory diseases. J Am Acad Dermatol 2016; 74:1153.
  68. Slade DE, Powell BW, Mortimer PS. Hidradenitis suppurativa: pathogenesis and management. Br J Plast Surg 2003; 56:451.
  69. Revuz J. Hidradenitis suppurativa. J Eur Acad Dermatol Venereol 2009; 23:985.
  70. Saunte DM, Boer J, Stratigos A, et al. Diagnostic delay in hidradenitis suppurativa is a global problem. Br J Dermatol 2015; 173:1546.
  71. Smith HS, Chao JD, Teitelbaum J. Painful hidradenitis suppurativa. Clin J Pain 2010; 26:435.
  72. Jemec GB, Hansen U. Histology of hidradenitis suppurativa. J Am Acad Dermatol 1996; 34:994.
  73. Poli F, Jemec GBE, Revuz J. Clinical presentation. In: Hidradenitis suppurativa, Jemecs GBE, Revuz J, Leyden JJ (Eds), Heidelberg, Germany 2006. p.12-15.
  74. Kamp S, Fiehn AM, Stenderup K, et al. Hidradenitis suppurativa: a disease of the absent sebaceous gland? Sebaceous gland number and volume are significantly reduced in uninvolved hair follicles from patients with hidradenitis suppurativa. Br J Dermatol 2011; 164:1017.
  75. Baughman SM, Cespedes RD. Unusual presentation of hidradenitis suppurativa with massive enlargement of penis. Urology 2004; 64:377.
  76. Riis PT, Vinding GR, Ring HC, Jemec GB. Disutility in Patients with Hidradenitis Suppurativa: A Cross-sectional Study Using EuroQoL-5D. Acta Derm Venereol 2016; 96:222.
  77. Onderdijk AJ, van der Zee HH, Esmann S, et al. Depression in patients with hidradenitis suppurativa. J Eur Acad Dermatol Venereol 2013; 27:473.
  78. Deckers IE, Kimball AB. The Handicap of Hidradenitis Suppurativa. Dermatol Clin 2016; 34:17.
  79. Ring HC, Theut Riis P, Zarchi K, et al. Prodromal symptoms in hidradenitis suppurativa. Clin Exp Dermatol 2017; 42:261.
  80. Hurley HJ. Axillary hyperhidrosis, apocrine bromhidrosis, hidradenitis suppurativa, and familial benign pemphigus: surgical approach. In: Dermatologic surgery, Roenigk RK, Roenigk HH (Eds), New York 1989. p.729.
  81. Shlyankevich J, Chen AJ, Kim GE, Kimball AB. Hidradenitis suppurativa is a systemic disease with substantial comorbidity burden: a chart-verified case-control analysis. J Am Acad Dermatol 2014; 71:1144.
  82. Miller IM, Ellervik C, Vinding GR, et al. Association of metabolic syndrome and hidradenitis suppurativa. JAMA Dermatol 2014; 150:1273.
  83. Gold DA, Reeder VJ, Mahan MG, Hamzavi IH. The prevalence of metabolic syndrome in patients with hidradenitis suppurativa. J Am Acad Dermatol 2014; 70:699.
  84. Tzellos T, Zouboulis CC, Gulliver W, et al. Cardiovascular disease risk factors in patients with hidradenitis suppurativa: a systematic review and meta-analysis of observational studies. Br J Dermatol 2015; 173:1142.
  85. González-López MA, Hernández JL, Lacalle M, et al. Increased prevalence of subclinical atherosclerosis in patients with hidradenitis suppurativa (HS). J Am Acad Dermatol 2016; 75:329.
  86. Egeberg A, Gislason GH, Hansen PR. Risk of Major Adverse Cardiovascular Events and All-Cause Mortality in Patients With Hidradenitis Suppurativa. JAMA Dermatol 2016; 152:429.
  87. Shalom G, Freud T, Ben Yakov G, et al. Hidradenitis Suppurativa and Inflammatory Bowel Disease: A Cross-Sectional Study of 3,207 Patients. J Invest Dermatol 2016; 136:1716.
  88. Yadav S, Singh S, Edakkanambeth Varayil J, et al. Hidradenitis Suppurativa in Patients With Inflammatory Bowel Disease: A Population-Based Cohort Study in Olmsted County, Minnesota. Clin Gastroenterol Hepatol 2016; 14:65.
  89. Scheinfeld NS. A case of dissecting cellulitis and a review of the literature. Dermatol Online J 2003; 9:8.
  90. Chicarilli ZN. Follicular occlusion triad: hidradenitis suppurativa, acne conglobata, and dissecting cellulitis of the scalp. Ann Plast Surg 1987; 18:230.
  91. Marzano AV, Trevisan V, Gattorno M, et al. Pyogenic arthritis, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PAPASH): a new autoinflammatory syndrome associated with a novel mutation of the PSTPIP1 gene. JAMA Dermatol 2013; 149:762.
  92. Braun-Falco M, Kovnerystyy O, Lohse P, Ruzicka T. Pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH)--a new autoinflammatory syndrome distinct from PAPA syndrome. J Am Acad Dermatol 2012; 66:409.
  93. Marzano AV, Ishak RS, Colombo A, et al. Pyoderma gangrenosum, acne and suppurative hidradenitis syndrome following bowel bypass surgery. Dermatology 2012; 225:215.
  94. Marzano AV, Ceccherini I, Gattorno M, et al. Association of pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH) shares genetic and cytokine profiles with other autoinflammatory diseases. Medicine (Baltimore) 2014; 93:e187.
  95. Calderón-Castrat X, Bancalari-Díaz D, Román-Curto C, et al. PSTPIP1 gene mutation in a pyoderma gangrenosum, acne and suppurative hidradenitis (PASH) syndrome. Br J Dermatol 2016; 175:194.
  96. Fimmel S, Zouboulis CC. Comorbidities of hidradenitis suppurativa (acne inversa). Dermatoendocrinol 2010; 2:9.
  97. Weedon D. Diseases of cutaneous appendages. In: Weedon's Skin Pathology, 3rd ed, Elsevier Limited, Edinburgh 2010. p.397.
  98. Wortsman X, Jemec GB. Real-time compound imaging ultrasound of hidradenitis suppurativa. Dermatol Surg 2007; 33:1340.
  99. Wortsman X, Castro A, Figueroa A. Color Doppler ultrasound assessment of morphology and types of fistulous tracts in hidradenitis suppurativa (HS). J Am Acad Dermatol 2016; 75:760.
  100. Wortsman X, Rodriguez C, Lobos C, et al. Ultrasound Diagnosis and Staging in Pediatric Hidradenitis Suppurativa. Pediatr Dermatol 2016; 33:e260.
  101. Griffin N, Williams AB, Anderson S, et al. Hidradenitis suppurativa: MRI features in anogenital disease. Dis Colon Rectum 2014; 57:762.
  102. von Laffert M, Stadie V, Ulrich J, et al. Morphology of pilonidal sinus disease: some evidence of its being a unilocalized type of hidradenitis suppurativa. Dermatology 2011; 223:349.
  103. Kibbi, AG, El-Shareef, M. Granuloma inguinale. In: Fitzpatrick's Dermatology in General Medicine, 7th ed, Wolff, K, Goldsmith, LA, Katz, SI, et al. (Eds), McGraw Hill, 2008. p.1990.
  104. Bhalla R, Sequeira W. Arthritis associated with hidradenitis suppurativa. Ann Rheum Dis 1994; 53:64.
  105. Scheinfeld N. Diseases associated with hidranitis suppurativa: part 2 of a series on hidradenitis. Dermatol Online J 2013; 19:18558.
  107. Anstey AV, Wilkinson JD, Lord P. Squamous cell carcinoma complicating hidradenitis suppurativa. Br J Dermatol 1990; 123:527.
  108. Mendonça H, Rebelo C, Fernandes A, et al. Squamous cell carcinoma arising in hidradenitis suppurativa. J Dermatol Surg Oncol 1991; 17:830.
  109. Zachary LS, Robson MC, Rachmaninoff N. Squamous cell carcinoma occurring in hidradenitis suppurativa. Ann Plast Surg 1987; 18:71.
  110. Lavogiez C, Delaporte E, Darras-Vercambre S, et al. Clinicopathological study of 13 cases of squamous cell carcinoma complicating hidradenitis suppurativa. Dermatology 2010; 220:147.
  111. Losanoff JE, Sochaki P, Khoury N, et al. Squamous cell carcinoma complicating chronic suppurative hydradenitis. Am Surg 2011; 77:1449.
  112. Maclean GM, Coleman DJ. Three fatal cases of squamous cell carcinoma arising in chronic perineal hidradenitis suppurativa. Ann R Coll Surg Engl 2007; 89:709.