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Hidradenitis Suppurativa

The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.

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NORD is very grateful to Robert Lee, MD, PhD, Assistant Clinical Professor, Dermatology; Director of Dermatopathology, University of California, San Diego, for assistance in the preparation of this report.

Synonyms of Hidradenitis Suppurativa

Disorder Subdivisions

General Discussion

Hidradenitis suppurativa (HS) is a chronic condition characterized by swollen, painful lesions, occurring in the armpit (axillae), groin, anal, and breast regions. This disease occurs due to obstruction of hair follicles and secondary infection and sometimes inflammation of certain sweat glands (apocrine glands). It is a progressive disease where single boil-like, pus-filled abscesses become hard lumps, then painful, deep-seated, often inflamed clusters of lesions with chronic seepage. Healing of affected areas is typically associated with progressive scarring (fibrosis). Formation of chronic epithelialized, sometimes interconnected, sinus tracts occur in severe disease. This often leads to the entrapment of perspiration and bacteria in the surrounding tissue, which causes the inflammation and infection. HS can be extremely painful and debilitating but is rarely life threatening; only occurring when the bacteria infection leads to an overwhelming systemic infection in an individual with a weakened immune system.

HS was once thought to be a rare disorder because only the most severe cases were reported. HS was first described in the medical literature by Velpeau in 1839 and was considered an extremely severe form of acne (acne inversa). It most often presents at puberty because changes in hair follicles triggered by the surge in sex hormones. The condition may also begin to occur in patients of any age after puberty, but rarely before. Cases vary in severity, but all require some treatment and management. For mild cases, home remedies may be all that is needed. For severe forms however, daily medication is often prescribed and radical surgery may eventually be recommended. Early diagnosis and treatment of HS is important because it can help manage symptoms and prevent new boils and lesions from forming.


HS is a chronic, inflammatory disease affecting sweat glands known as apocrine glands. In most individuals with HS, recurrent lesions develop in the axillae, groin, vulva, or anal region. However, in some cases, the condition may involve sweat glands of the breasts, scalp, or other areas. Evidence suggests that females are more commonly affected in the axillary or vulvar region, while males primarily have involvement around the anal region.

Although the age at onset may vary, symptoms often become apparent during puberty or early adulthood. The disease has a duration of many years, with periodic improvement and worsening of symptoms. Many things can trigger flare-ups of this disease including menstruation for women, weight gain, stress, hormonal changes, heat, and perspiration. In some cases, early symptoms, such as itching or discomfort, may precede the condition's characteristic manifestations.

There are 3 clinical stages of HS. Each stage is best treated with different therapies. Ideally, treatment would stop the progression to stage 3 for as long as possible. However, HS has no cure and the disease will eventually follow its course. These stages are as follows:

Harley stage 1: In some cases, early symptoms, such as itching or discomfort, may precede the condition's characteristic manifestations.

Harley stage 2: Recurrent abscesses form, with tract formation and scar formation. There may be single or multiple widely separated lesions.

Harley stage 3: Diffuse or near-diffuse involvement or multiple interconnected tracts and abscesses are observed across the entire area.

Obstruction (occlusion) of hair follicles and follicular rupture leads to the development of tender or painful, reddish nodules and pus-containing cavities of infection (abscesses). Abscesses may spontaneously rupture through the skin, draining pus that may be mingled with a clear fluid (seropurulent) that often has an unpleasant odor. With healing, scar tissue forms and new lesions may develop adjacent to the initial nodules. In some severe cases, deep abscesses may drain via abnormal channels deep within skin tissues that connect them to the body's surface (sinus tract formation). Repeated healing and recurrences result in progressive scarring of affected tissues that may appear as thick, cordlike bands. In extremely severe cases, the condition may become extensive and potentially disabling.


The exact underlying cause of HS is unknown, but the condition probably results from a combination of genetic and environmental factors.

Symptoms result from abnormal obstruction (occlusion) of hair follicles and secondary bacterial infection and inflammation, with subsequent rupture of the ducts, spread of infection, and scarring. Another possible cause is abnormal gland development.

Some affected individuals have a family history of the disease, suggesting that genetic factors may play a causative role. . The molecular complex gamma-secretase has been implicated in familial cases of HS.

Affected Populations

HS affects females about three times more often than males. Approximately 1/100 people are affected when mild cases are included. The condition typically becomes apparent during puberty but almost never after the age of about 40.

Related Disorders

Symptoms of the following disorders may be similar to those of hidradenitis suppurativa. Comparisons may be useful for a differential diagnosis:

Furunculosis is characterized by the development of inflammatory nodules known as boils or furuncles due to infection with staphylococcus bacteria. Boils are red, tender or painful lumps that discharge a central core of tissue and pus. They may sometimes recur. Contributing factors that make a person vulnerable to boils may include obesity, diabetes mellitus, and poor hygiene.

Tuberculosis of the skin is an infectious disease caused by the Mycobacterium tuberculosis bacteria.

Crohn’s disease is an inflammatory bowel disease which rarely can have cutaneous manifestations of sinus tracts and fistulas which can simulate HS.

There are a number of additional diseases that may be characterized by symptoms similar to those associated with HS. (For further information, choose the specific disease name in question as your search term in the Rare Disease Database.)

Standard Therapies

HS often goes undiagnosed for years because patients are too ashamed to speak with anyone about their symptoms. A diagnosis is made based upon symptoms, medical history, examination and blood tests. If pus or fluid drainage is present, a sample of fluid may be sent for a culture test in order to rule out other skin conditions.

Clinical Testing and Work-Up
Ultrasonography of hair follicles and the thickness of the skin can reveal abnormalities and show how the disease is progressing. Other tests that have been used in evaluating the stage of the disease are C-reactive protein assay, urinalysis, serum IL-2 receptor levels assessment of the erythrocyte sedimentation rate, and a CBC count with differential and platelet counts.

There is no known cure for HS. Treatment depends on what clinical stage a patient is at and the severity of their condition. Furthermore, what works for one patient may not work for another. Mild HS can usually be managed with home remedies such as the application of warm compresses, good hygiene, antibacterial soaps, antiseptics, anti-inflammatory medication, and wearing loose-fitting clothing. It is also important for HS patients to maintain a healthy weight and to not smoke. Overweight individuals experience more friction on their body which irritates the skin. They also are more prone to excessive perspiration. Both aid in irritating the skin which causes flare-ups. Smoking also has been shown to be associated more severe disease.

A great number of HS patients have a hard time properly maintaining their weight because exercise causes them pain. Staying healthy is highly important to slowing the progression of the disease, so every effort to find a comfortable exercise routine should be exerted. A lot of patients have reported that swimming not only is great for staying in shape, but provides temporary relief from the painful lesions.

Moderate and severe cases of HS may require medications. Possible medications include antibiotics, oral retinoid medication, anti-inflammatory drugs, corticosteroids, hormones, and tumor necrosis factor-alpha inhibitors. Other treatments that have been shown to be of some benefit are carbon dioxide laser therapy, laser hair removal, radiation therapy, surgery.

Surgical removal of lesions and skin grafting of affected areas may be necessary in cases of extensive, persistent scarred lesions. This surgery is extensive because not only must the skin containing the lesions be removed, but wide margins around the affected area must be removed as well. Surgery has long been considered a cure for this disease, but specific studies have shown otherwise. Ideally, the disease would disappear in the areas that were grafted with new skin; however, recurrence rates can be high particularly if only narrow margins are taken. More limited surgical intervention, consisting of draining abscesses and sinus tracts can be useful for palliation of symptoms but these lesions almost invariably recur.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:

Hidradenitis Suppurativa Resources



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Behrman RE, et al, eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia, PA: W.B. Saunders Company; 2000:2020-21.

Jemec, GB. Clinical practice. Hidradenitis suppurativa. N Engl J Med. 2012;366(2):158-64.
Wang, B et al. Gamma-secretase gene mutations in familial acne inversa. Science. 2010;330(6007):1065.

Elwood ET, et al. Negative-pressure dressings in the treatment of hidradenitis suppurativa. Ann Plast Surg. 2001;46:49-51.

Bohn J, et al. Surgical treatment of hidradenitis suppurativa. Scand J Plast Reconstr Surg Hand Surg. 2001;35:305-09.

Mengesha YM, et al. Prepubertal hidradenitis suppurativa: two case reports and review of the literature. Pediatr Dermatol. 1999;16:292-96.

Konig A, et al. Cigarette smoking as a triggering factor of hidradenitis suppurativa. Dermatology. 1999;198:261-64.

Boer J, et al. Long-term results of isotretinoin in the treatment of 68 patients with hidradenitis suppurativa. J Am Acad Dermatol. 1999;40:73-76.

Brown TJ, et al. Hidradenitis suppurativa. South Med J. 1998;91:1107-14.

Brown CF, et al. Hidradenitis suppurativa of the anogenital region: response to isotretinoin. Am J Obstet Gynecol. 1988;158:12-15.

Mortimer PS, et al. A double-blind controlled cross-over trial of cyproterone acetate in females with hidradenitis suppurativa. Br J Dermatol. 1986;115:263-68.

Sawers RS, et al. Control of hidradenitis suppurativa in women using combined antiandrogen (cyproterone acetate) and oestrogen therapy. Br J Dermatol. 1986; 115:269-74.

Watson JD. Hidradenitis suppurativa--a clinical review. Br J Plast Surg. 1985;38:567-69.

Dicken CH, et al. Evaluation of isotretinoin treatment of hidradenitis suppurativa. J Am Acad Dermatol. 1984;11:500-02.

Online Mendelian Inheritance in Man (OMIM). The Johns Hopkins University. Acne Inversa, Familial, 1; ACNINV1. Entry No: 142690. Last Edited December 12, 2011. Available at: http://www.ncbi.nlm.nih.gov/omim/. Accessed September 12, 2012.

Hidradenitis suppurativa. Mayo Clinic. http://www.mayoclinic.com/health/hidradenitis-suppurativa/DS00818. Last updated September 21, 2010. Accessed September 12, 2012.

What is hidradenitis suppurativa? HS-usa.org. http://hs-usa.org//hidradenitis_suppurativa.htm. Accessed September 12, 2012

Fite D. Hidradenitis Suppurativa in Emergency Medicine. Emedicine. http://emedicine.medscape.com/article/762444-overview. Updated July 10, 2012. Accessed September 12, 2012.

Hidradenitis suppurativa. Genetics Home Reference. http://ghr.nlm.nih.gov/condition/hidradenitis-suppurativa. Reviewed March 2010. Published April 16, 2012. Accessed September 12, 2012.

Report last updated: 2012/09/14 00:00:00 GMT+0