|Classification and external resources|
|eMedicine||emerg/259 med/2717 derm/892|
Hidradenitis suppurativa (HS) is a skin disease characterized by clusters of chronic abscesses, epidermoid cysts, sebaceous cysts, pilonidal cyst or multilocalised infections that most commonly affects areas bearing apocrine sweat glands, such as the underarms, under the breasts, inner thighs, groin and buttocks. The disease is not contagious.
The cysts seen in HS can be extremely tender and may persist for years with interspersed periods of inflammation, culminating in incision and drainage of pus from the cyst. This process often forms open wounds that will not heal. For unknown reasons, people with HS develop plugging or clogging of their apocrine glands. HS causes chronic scarring and pus formation of the underarms, groin, and inner thighs. The simple procedure of incision and drainage may provide symptomatic relief. HS flares may be triggered by perspiration, hormonal changes (such as those seen with the menstrual cycle), humidity and heat, and friction from clothing.
Persistent lesions may lead to scarring and the formation of sinus tracts, or tunnels connecting the abscesses or infections under the skin. At this stage, complete healing is usually not possible, and progression is variable, with some experiencing remission for months to years at a time, while others may worsen and require multiple surgeries. Bacterial infections and cellulitis (deep tissue inflammation) are other common complications of HS. Hidradenitis suppurativa pain and depression can be difficult to manage.
HS often goes undiagnosed for years due to a delay in seeking treatment and is frequently misdiagnosed. There is currently no known cure nor any consistently effective treatment. Nutritional strategies of avoiding all inflammatory foods, i.e. eliminating sugar and fruit juices entirely and cutting out wheat, dairy eggs and particularly avoiding foods of the nightshade family (potatoes, tomatoes, peppers) has been associated remission of symptoms in sufferers. Carbon dioxide laser surgery is currently considered the last resort for advanced disease. HS is an orphan disease due to sparse research efforts. Sufferers may gain insight into how best to control their flare-ups by following blogs written by fellow sufferers. The disease's incidence rate is not well established, but has been estimated as being between 1:24 (4.1%) and 1:600 (0.2%).[medical citation needed]
- 1 Causes
- 2 Stages
- 3 Treatments
- 4 Prognosis
- 5 History
- 6 In Popular Culture
- 7 References
- 8 External links
Hidradenitis suppurativa is a poorly studied disease and its cause remains unknown. Experts disagree over proposed causes.
HS occurs when hair follicles become plugged.[vague] Lesions occur in any body areas with hair follicle although intertriginous areas such as the axilla, groin, and perianal region are more commonly involved. This theory includes most of the following potentials indicators:
- Post-pubescent individuals are more likely to exhibit HS.
- Plugged apocrine (sweat) gland or hair follicle.
- Excessive sweating.
- Sometimes linked with other auto-immune conditions.
- Androgen dysfunction.
- Genetic disorders that alter cell structure.
- Patients with more advanced cases may find exercise intolerably painful, which may increase the rate of obesity among sufferers.
The historical understanding of the disease is that there are dysfunctional apocrine glands or dysfunctional hair follicles, possibly triggered by a blocked gland, creating inflammation, pain, and a swollen lesion.
- Obesity is an exacerbating rather than a triggering factor, through mechanical irritation, occlusion, and maceration.
- Tight clothing, and clothing made of heavy, non-breathable materials.
-  Deodorants, depilation products, shaving of the affected area – their association with hidradenitis suppurativa is still an ongoing debate amongst researchers.
- Drugs, in particular oral contraceptives (i.e., oral hormonal birth control; "the pill") and lithium.
- Hot and especially humid climates (dry/arid climates often cause remission).
- Genetic factors: an autosomal dominant inheritance pattern has been postulated.
- Endocrine factors: sex hormones, principally an excess of androgens, are thought to be involved, although the apocrine glands are not sensitive to these hormones. Women often have outbreaks before menstruation and post-pregnancy, and the disease usually remits during pregnancy and after menopause.
Hurley's staging system
This is historically the first classification system proposed, and is still in use for the classification of patients with skin/dermatologic diseases (i.e., psoriasis, HS, acne). Hurley separated patients into three groups based largely on the presence and extent of cicatrization and sinuses. It has been used as a basis for clinical trials in the past and is a useful basis to approach therapy for patients. These three stages are based on Hurley's staging system, which is simple and relies on the subjective extent of the diseased tissue the patient has. Hurley's three stages of hidradenitis suppurativa are as follows:
|I||Solitary or multiple isolated abscess formation without scarring or sinus tracts. (A few minor sites with rare inflammation; may be mistaken for acne.)|
|II||Recurrent abscesses, single or multiple widely separated lesions, with sinus tract formation. (Frequent inflammation restrict movement and may require minor surgery such as incision and drainage.)|
|III||Diffuse or broad involvement across a regional area with multiple interconnected sinus tracts and abscesses. (Inflammation of sites to the size of golf balls, or sometimes baseballs; scarring develops, including subcutaneous tracts of infection – see fistula. Obviously, patients at this stage may be unable to function.)|
Sartorious staging system
The Sartorious staging system is more sophisticated than Hurley's. Sartorius et al. suggested that the Hurley system is not sophisticated enough to assess treatment effects in clinical trials during research. This classification allows for better dynamic monitoring of the disease severity in individual patients. The elements of this staging system are the following:
- Anatomic regions involved (axilla, groin gluteal or other region or infra-mammary region left or right)
- Number and types of lesions involved (abscesses, nodules, fistulas, scars, points for lesions of all regions involved)
- The distance between lesions, in particular the longest distance between two relevant lesions (i.e., nodules and fistulas in each region or size if only one lesion present)
- The presence of normal skin in between lesions (i.e., are all lesions clearly separated by normal skin?)
Points are accumulated in each of the above categories, and added to give both a regional and total score. In addition, the authors recommend adding a visual analog scale for pain or using the dermatology life quality index (DLQI, or the Skindex) when assessing HS.
Treatments may vary depending upon presentation and severity of the disease. Due to the poorly studied nature of this disease, the effectiveness of the drugs and therapies listed below is unclear, and patients should discuss all options with their physician or dermatologist. Nearly a quarter of patients state that nothing relieves their symptoms. Possible treatments include the following:
- Changes in diet avoiding inflammatory foods, foods high in refined carbohydrates.
- Warm compresses with distilled vinegar water, and taking hot baths with distilled white vinegar in the water hydrotherapy, balneotherapy.
- Icing the inflamed area daily until pain reduction is noticed.
- Weight loss in overweight and obese patients, as well as smoking cessation can improve or even alleviate many symptoms of hidradenitis suppurativa.
- Washing with benzoyl peroxide can be effective.
- Antibiotics- taken orally, these are used for their anti-inflammatory properties rather than to treat infection. Most effective is a combination of rifampicin and clindamycin given concurrently for 2–3 months. This brings about remission in around three quarters of cases. A few popular antibiotics used to treat hidradenitis suppurativa include tetracycline, minocycline, and clindamycin.
- Corticosteroid injections. Also known as intralesional steroids: can be particularly useful for localized disease, if the drug can be prevented from escaping via the sinuses.
- Vitamin A supplementation
- Anti-androgen therapy: hormonal therapy with cyproterone acetate and ethinyl estradiol proved effective in randomized, controlled trials. Dosages reported have been very high.
- Intravenous or subcutaneous infusion of anti-inflammatory (anti-TNF-alpha) drugs such as infliximab (Remicade), etanercept (Enbrel), and adalimumab (Humira). This use of these drugs is not currently Food and Drug Administration (FDA) approved and is somewhat controversial, and therefore may not be covered by insurance.
- Zinc gluconate taken orally has been shown to induce remission.
- Chlorhexidine (Hibiclens) plus an antibiotic soap for cleansing the skin surface. Covering sores with Metrolotion after medicated showers. These are considered to be general measures and are the foundation of any good medical treatment and management plan for hidradenitis suppurativa.
- Topical clindamycin has been shown to have an effect in double-blind placebo controlled studies.
- Topical resorcinol is a keratolytic agent that targets the follicular keratin plug and has been shown to have efficacy in several case series studies.
Electron beam radiotherapy has been a successful treatment of hidradenitis, especially in Europe; it is not a common treatment option in most of the United States, as radiation oncologists generally refuse to treat patients with non-malignant diseases because of the potential for secondary radiation-induced tumors in the long term.
When the process becomes chronic, wide surgical excision is the procedure of choice. Wounds in the affected area do not heal by secondary intention, and immediate application of a split thickness skin graft is more appropriate.
Laser Hair Removal
In stage III disease, fistulas left undiscovered, undiagnosed, or untreated, can lead to the development of squamous cell carcinoma, a rare cancer, in the anus or other affected areas. Other stage III chronic sequelae may also include anemia, multilocalized infections, amyloidosis, and arthropathy. Stage III complications have been known to lead to death, but clinical data is still uncertain.
- Contractures and reduced mobility of the lower limbs and axillae due to fibrosis and scarring. Severe lymphedema may develop in the lower limbs.
- Local and systemic infections (meningitis, bronchitis, pneumonia, etc.), which may even progress to sepsis.
- Interstitial keratitis.
- Anal, rectal, or urethral fistulas in anogenital hidradenitis suppurativa.
- Normochromic or hypochromic anemia.
- Squamous cell carcinoma: this has been found on rare occasions in chronic hidradenitis suppurativa of the anogenital region. The mean time to the onset of this type of lesion is 10 years or more and the tumors are usually highly aggressive.
- Tumors of the lung and oral cavity, probably related to the high level of smoking among these patients, and liver cancer.
- Hypoproteinemia and amyloidosis, which can lead to renal failure and death.
- Seronegative and usually asymmetric arthropathy: pauciarticular arthritis, polyarthritis/polyarthralgia syndrome.
- In 1839, Velpeau identified and described hidradenitis suppurativa.
- In 1854, Verneuil described hidradenitis suppurativa as "Hidrosadénite Phlegmoneuse". This is how HS obtained its alternate name "Verneuil's disease".
- In 1922, Schiefferdecker hypothesized a pathogenic link between "Acne inversa" and human apocrine sweat glands.
- In 1956, Pillsbury wrote and published a medical journal article discussing hidradenitis suppurativa, describing the disease's main characteristics, dubbing them the "Acne triad: hidradenitis suppurativa, perifolliculitis capitis abscedens et suffodiens". Pillsbury's research study was one of the first peer-reviewed journal articles to appear publicly with many details of hidradenitis suppurativa, which are still used and relied on today in the medical realm of research on this disease.
- In 1975, Plewig and Kligman, following Pillsbury's research path, modified the "Acne triad", replacing it with the "Acne tetrad: acne triad, plus pilonidal sinus". Plewig and Kligman's research follows in Pillsbury's footsteps, offering explanations of the symptoms associated with hidradenitis suppurativa.
- In 1989, Plewig and Steger's research led them to rename hidradenitis suppurativa, calling it "Acne Inversa" – which is not still used today in medical terminology; although some individuals still use this outdated term.
A surgeon from Paris, Velpeau described an unusual inflammatory process with formation of superficial axillary, sub-mammary and perianal abscesses in 1839. One of his colleagues also located in Paris, named Verneuil, coined the term “hidrosadénite phlegmoneuse” approximately 15 years later. This name for the disease reflects the former pathogenetic model of acne inversa, which is considered inflammation of sweat glands as the primary cause of hidradenitis suppurativa. In 1922 Schiefferdecker suspected a pathogenicassociation between acne inversa and apocrine sweat glands. In 1956 Pillsbury postulated follicular occlusion as the cause of acne inversa, which they grouped together with acne conglobata and perifolliculitis capitis abscendens et suffodiens (dissecting cellulitis of the scalp) as the "acne triad". Plewig and Kligman added another element to their acne triad, pilonidal sinus. Plewig et al. noted that this new "acne tetrad" includes all the elements found in the original "acne triad", in addition to a fourth element, pilonidal sinus. In 1989, Plewig and Steger introduced the term "acne inversa", indicating a follicular source of the disease and replacing older terms such as "Verneuil disease".
|Velpeau||1839||First description of the hidradenitis suppurativa|
|Pillsbury||1956||Acne triad (hidradenitis suppurativa, perifolliculitis capitis abscendens et suffodiens)|
|Plewig & Kligman||1975||Acne tetrad (acne triad + pilonidal sinus)|
|Plewig & Steger||1989||Acne inversa|
Hidradenitis suppurativa has been referred to by multiple names in the literature, as well as in various cultures. Some of these are also used to describe different diseases, or specific instances of this disease.
- Acne conglobata – not really a synonym – this is a similar process but in classic acne areas of chest and back
- Acne Inversa (AI) – a proposed new term which has not gained widespread favor.
- Apocrine Acne – a misnomer, out-dated, based on the disproven concept that apocrine glands are primarily involved. Though many do suffer with apocrine gland infection, so thought should be given to using HS with subtext re: glands involved.
- Apocrinitis – another misnomer, out-dated, based on the disproven concept that apocrine glands are primarily involved
- Fox-den disease – a term not used in medical literature, based on the deep fox den / burrow – like sinuses
- Hidradenitis Supportiva – a misspelling
- Pyodermia fistulans significa – now considered archaic
- Velpeau's disease – commemorating the French surgeon who first described the disease in 1833
- Verneuil's disease – recognizing the French surgeon whose name is most often associated with the disorder as a result of his 1854–1865 studies
Dermatohistological view of hidradenitis suppurativa
|Plewig & Steger||1989||Initial hyperkeratosis of the follicular infundibulum. Bacterial super-infection and follicle rupture. Granulomatous inflammatory reaction of the connective tissue. Apocrine and eccrine sweat glands secondarily involved.|
|Yu & Cook||1990||Cysts and sinus tracts lined with epithelium, in part with hair shafts. Inflammation of apocrine sweat glands only if eccrine sweat glands and hair follicles are also inflamed.|
|Boer & Weltevreden||1996||Primary inflammation of the follicular infundibulum. Apocrine sweat glands are secondarily involved.|
In Popular Culture
Hidradenitis suppurativa was mentioned on 8 Out of 10 Cats, Season 17 Episode 6.
- Alikhan, Ali; Lynch, Eisen (2009). "Hidradenitis suppurativa: a comprehensive review". J Am Acad Derm 60 (4): 539–561. doi:10.1016/j.jaad.2008.11.911. PMID 19293006.
- Mayo Clinic Staff. "Causes". Mayo Clinic. Retrieved 19 September 2012.
- "Mayo Clinic site". Retrieved 2013-12-07.
- "HS-USA :: What is Hidradenitis Suppurativa?". Retrieved 2013-07-20.
- "HS-USA: Prevalence of Hidradenitis Suppurativa". Retrieved 2007-07-08.
- Medline Plus (2012). "Hidradenitis suppurativa". U.S. National Library of Medicine. Retrieved 19 September 2012.
- Schawartz's principles of surgery, 8th edition, self assessment an board review, chapter 15, the skin and subcutaneous tissue, question 16
- Mayo Clinic Staff (2012). "Definition". Mayo Clinic. Retrieved 19 September 2012.
- ClinicalTrials.gov NCT00329823 Etanercept in Hidradenitis Suppurativa
- Cusack C, Buckley C (2006). "Etanercept: effective in the management of hidradenitis suppurativa". Br J Dermatol 154 (4): 726–9. doi:10.1111/j.1365-2133.2005.07067.x. PMID 16536817.
- DermNet acne/hidradenitis-suppurativa
- "HSF – What is Hidradenitis Suppurativa? What is HS?". Retrieved 2007-07-08.
- Slade DEM, Powell BW, Mortimer PS (2003). "Hidradenitis suppurativa: pathogenesis and management". Br J Plast Surg 56 (5): 451–61. doi:10.1016/S0007-1226(03)00177-2. PMID 12890458.
- Jemec GBE. Body weight in hidradenitis suppurativa. In: Marks R, Plewig G, editors. Acne and Related disorders. London: Martin Dunitz; 1989. pp. 375–6.
- Koning A, Lehmann C, Rompel R, Happle R (1999). "of Hidradenitis suppurativa". Dermatology 198 (3): 261–4. doi:10.1159/000018126. PMID 10393449.
- Morgan WP, Leicester G (1979). "The role of depilation and deodorants in hidradenitis suppurativa". Br J Surg 66 (12): 853–6. doi:10.1002/bjs.1800661206. PMID 509057.
- Stellon AJ, Wakeling M (1989). "Hidradenitis suppurativa associated with use of oral contraceptives". Br Med J 298 (6665): 28–9. doi:10.1136/bmj.298.6665.28.
- Gupta AK, Knowles SR, Gupta MA, Jaunkalns R, Shear NH (1995). "Lithium therapy associated with hidradenitis suppurativa: case report and a review of the dermatologic side effects of lithium". J Am Acad Dermatol 32 (2 Pt 2): 382–6. doi:10.1016/0190-9622(95)90410-7. PMID 7829746.
- Medscape: Medscape Access. Emedicine.medscape.com. Retrieved on 2011-11-06.
- Der Werth JM, Williams HC, Raeburn JA (2000). "The clinical genetics of hidradenitis suppurativa revisited". Br J Dermatol 142 (5): 947–53. doi:10.1046/j.1365-2133.2000.03476.x. PMID 10809853.
- Barth JH, Kealey T (1991). "Androgen metabolism by isolated human axillary apocrine glands in hidradenitis suppurativa". Br J Dermatol 125 (4): 304–8. doi:10.1111/j.1365-2133.1991.tb14162.x. PMID 1954117.
- Hurley HJ. Axillary hyperhidrosis, apocrine bromhidrosis, hidradenitis suppurativa, and familial benign pemphigus: surgical approach. In: Roenigk RK, Roenigk HH, editors. Dermatologic surgery. Marcel Dekker, New York, 1989, pp. 729–739.
- Sartorius K, Lapins J, Emtestam L, Jemec GB (2003). "Suggestions for uniform outcome variables when reporting treatment effects in hidradenitis suppurativa". Br J Dermatol 149 (1): 211–213. doi:10.1046/j.1365-2133.2003.05390.x. PMID 12890229.
- Wolkenstein, P; Loundou, A; Barrau, K; Auquier, P; Revuz, J; Quality of Life Group of the French Society of Dermatology (2007). "Quality of life impairment in hidradenitis suppurativa: a study of 61 cases". Journal of the American Academy of Dermatology 56 (4): 621–3. doi:10.1016/j.jaad.2006.08.061. PMID 17097366.
- "About Hidradenitis Suppurativa". abscesses.org. Retrieved 2007-07-08.
- Martinez F, Nos P, Benlloch S, Ponce J (2001). "Hidradenitis suppurativa and Crohn's disease: response to treatment with infliximab". Inflammatory Bowel Dis 7 (4): 323–326. doi:10.1097/00054725-200111000-00008. PMID 11720323.
- Hidradenitis suppurativa from DermNet by the New Zealand Dermatological Society. By Author: Vanessa Ngan, staff writer., Dr Amanda Oakley, Dermatologist. Last updated 29 Dec 2013
- Gener G; Canoui-Poitrine F; Revuz JE et al. (2009). "Combination therapy with clindamycin and rifampicin for hidradenitis suppurativa: a series of 116 consecutive patients". Dermatology (Basel) 219 (2): 148–54. doi:10.1159/000228334. PMID 19590173.
- Scheinfeld N (2013). "Hidradenitis suppurativa: A practical review of possible medical treatments based on over 350 hidradenitis patients". Dermatology Online Journal 19 (4): 1. PMID 24021361.
- Mortimer PS, Dawber RP, Gales MA, Moore RA (1986). "A double blind controlled cross-over trial of cyproterone acetate in females with hidradenitis suppurativa". Br J Dermatol 115 (3): 263–8. doi:10.1111/j.1365-2133.1986.tb05740.x. PMID 2944534.
- Cusack C, Buckley C (2006). "Etanercept: effective in the management of hidradenitis suppurativa". Br. J. Dermatol. 154 (4): 726–9. doi:10.1111/j.1365-2133.2005.07067.x. PMID 16536817.
- Scheinfeld N (2006). "Treatment of coincident seronegative arthritis and hidradentis supprativa with adalimumab". J. Am. Acad. Dermatol. 55 (1): 163–4. doi:10.1016/j.jaad.2006.01.024. PMID 16781316.
- Anabelle Brocard, Anne-Chantal Knol, Amir Khammari, Brigitte Dréno (2007). "Hidradenitis Suppurativa and Zinc: A New Therapeutic Approach". Dermatology 214 (4): 325–7. doi:10.1159/000100883. PMID 17460404.
- Clemmenson OJ (1983). "Topical treatment of hidradenitis suppurativa with clindamycin". Int J Dermatol 22 (5): 325–8. doi:10.1111/j.1365-4362.1983.tb02150.x. PMID 6347922.
- Boer, J; Jemec, GB (2010). "Resorcinol peels as a possible self-treatment of painful nodules in hidradenitis suppurativa.". Clin Exp Dermatol 35 (1): 36–40. doi:10.1111/j.1365-2230.2009.03377.x. PMID 19549239.
- "Hidradenitis suppurativa: A practical review of possible medical treatments based on over 350 hidradenitis patients.". http://escholarship.org. Retrieved 2014-03-04.
- Talmant JC, Bruant-Rodier C, Nunziata AC, Rodier JF, Wilk A (2006). "[Squamous cell carcinoma arising in Verneuil's disease: two cases and literature review]". Ann Chir Plast Esthet (in French) 51 (1): 82–6. doi:10.1016/j.anplas.2005.11.002. PMID 16488526.
- Short KA, Kalu G, Mortimer PS, Higgins EM (2005). "Vulval squamous cell carcinoma arising in chronic hidradenitis suppurativa". Clin. Exp. Dermatol. 30 (5): 481–3. doi:10.1111/j.1365-2230.2005.01875.x. PMID 16045671.
- Hurley HJJ. Apocrine glands. New York: McGraw Hill; 1979.
- Tennant F Jr, Bergeron JR, Stone OJ, Mullins JF (1968). "Anemia associated with hidradenitis suppurativa". Arch Dermatol 98 (2): 138–40. doi:10.1001/archderm.98.2.138. PMID 5667225.
- Williams ST, Busby RC, DeMuth RJ, Nelson H (1991). "Perineal hidradenitis suppurativa: presentation of two unusual complications and a review". Ann Plast Surg 26 (5): 456–62. doi:10.1097/00000637-199105000-00008. PMID 1952719.
- Lapins J, Ye W, Nyren O, Emtestam L (2001). "Incidence of cancer among patients with hidradenitis suppurativa". Arch Dermatol 137 (6): 730–4. PMID 11405761.
- Moschella SL (1966). "Hidradenitis suppurativa. Complications resulting in death". JAMA 198 (1): 201–3. doi:10.1001/jama.198.1.201. PMID 5953172.
- Vasey FB, Fenske NA, Clement GB, Bridgeford PH, Germain BF, Espinoza LR (1984). "Immunological studies of the arthritis of acne conglobata and hidradenitis suppurativa". Clin Exp Rheumatol 2 (4): 309–11. PMID 6241861.
- Velpeau A. Aissele. In: Bechet Jeune Z: Dictionnaire de médecine, on Repertoire Générale des Sciences Medicals sous le Rapport Theorique et Pratique. 1839.
- Verneuil AS (1854). "Etudes sur les tumeurs de la peau et quelques maladies de glandes sudoripares". Arch Gen Med 94: 693–705.
- Schiefferdecker B. Die Hautdrüsen der Menschen und der Säugetiere, ihre histologische und rassenanatomische Bedeutung sowie die muscularis sexualis. In: Schweizerbart E (Hrsg), Stuttgart: 1922.
- Pillsbury DM, Shelley WB, Kligmann AM. Bacterial infections of the skin. In: Pillsbury DM: Dermatoloy. 1st ed. Philadelphia: 1956: 482–9.
- Plewig G, Kligman A. Acne. Morphogenesis and Treatment. Berlin: Springer, 1975: 192–3.
- Plewig G, Steger M. Acne inversa (alias acne triad, acne tetrad or hidradenitis suppurativa). In: Marks R, Plewig G: Acne and related disorders. London: Martin Dunitz; 1989: 345–57.
- Sellheyer K; Krahl D. (2005). ""Hidradenitis suppurativa" is acne inversa! An appeal to (finally) abandon a misnomer". International Journal of Dermatology 44 (7): 535–40. doi:10.1111/j.1365-4632.2004.02536.x. PMID 15985019.
- Bazex, J, Bayle, P, San, B. (2007). "Hidradenitis suppurativa is acne inversa". International Journal of Dermatology 46 (3): 330. doi:10.1111/j.1365-4632.2007.02872.x. PMID 17343599.
- Scheinfeld N (2006). "Hidradenitis should not be renamed acne inversa". Dermatol. Online J. 12 (7): 6. PMID 17459292.
- Verneuil AS (1854). "Etudes sur les tumor de la peau". Arch Gen Med (in French) 94: 693.
- Yu C. and Cook M. (1990). "Hidradenitis suppurativa: a disease of follicular epithelium, rather than apocrine glands". Br J Dermatology 122 (6): 763–69. doi:10.1111/j.1365-2133.1990.tb06264.x. PMID 2369556.
- Boer J, Weltevreden EF (1996). "Hidradenitis suppurativa or Acne inversa. A clinicopathological study of early lesions". Br J Dermatol 135 (5): 721–5. doi:10.1111/j.1365-2133.1996.tb03880.x. PMID 8977671.
- The Hidradenitis Suppurativa Trust The HS Trust is a UK registered charity
- Medline: What is Hidradenitis Suppurativa?
- The Doctor's Doctor
- Hidradenitis Suppurativa (2004) Prof J. Revuz
- Hidradenitis Suppurativa Links
- Hidradenitis Suppurativa Foundation A Foundation site for sufferers of Hidradenitis Suppurativa
- HS-USA HS-USA is a nonprofit public 501c3 charity incorporated in the State of Michigan, USA.