Hidradenitis Suppurativa

Updated: May 19, 2016
  • Author: Marina Jovanovic, MD, PhD; Chief Editor: William D James, MD  more...
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Practice Essentials

Hidradenitis suppurativa is a disorder of the terminal follicular epithelium in the apocrine gland–bearing skin. This condition is a chronic disabling disorder that relentlessly progresses, frequently causing keloids, contractures, and immobility. See the image below.

Close-up view of axillary hidradenitis suppurativa Close-up view of axillary hidradenitis suppurativa in a patient with pyoderma gangrenosum.

Signs and symptoms

Hidradenitis suppurativa usually occurs in otherwise healthy adolescents and adults. It rarely may begin before puberty. Hidradenitis suppurativa is characterized by comedolike follicular occlusion, chronic relapsing inflammation, mucopurulent discharge, and progressive scarring.

The onset of hidradenitis suppurativa is insidious, with the earliest sign being erythema. Later, the lesions become painful. Arthropathy associated with hidradenitis suppurativa may present with variable clinical features, ranging from asymmetric pauciarticular arthritis to a symmetric polyarthritis and/or polyarthralgia syndrome, as well as spondyloarthropathy. Moreover, epidemiological data also suggest an association of hidradenitis suppurativa with other diseases, including metabolic syndrome. Therefore, it is important to approach hidradenitis suppurativa as a systemic disease with an interprofessional team. [1, 2]

See Clinical Presentation for more detail.


The diagnosis is primarily clinical, no pathognomonic test exists, and biopsy is rarely required, especially in well-developed lesions. [3] The consensus approach indicates that three key elements are required to diagnose hidradenitis suppurativa: typical lesions, characteristic distribution, and recurrence. Arbitrarily, two recurrences over a period of 6 months have been used as a qualifier for a diagnosis. [3] All three criteria must be present for the definitive diagnosis. [1]

Primary positive diagnostic criteria are as follows:

  • History: Recurrent painful or suppurating lesions more than twice in 6 months
  • Signs: Involvement of axilla, genitofemoral area, perineum, gluteal area and inframammary area of women; presence of nodules (inflamed or noninflamed), sinus tracts (inflamed or noninflamed), abscesses, and scarring (atrophic, meshlike, red, hypertrophic or linear)

Suspicion of the diagnosis can be strengthened by other factors that are not, however, pathognomonic. [1, 3]

Secondary positive diagnostic criteria are as follows:

  • History: Family history of hidradenitis suppurativa
  •  Microbiology: A negative swab or the presence of normal skin microbiota (may be indicative of hidradenitis suppurativa)

Typical lesions, called primary lesions, include the following:

  • Painful and/or tender erythematous papules smaller than 1 cm in diameter
  • Painful and/or tender erythematous nodules larger than 1 cm in diameter
  • Painful or tender abscesses and inflamed discharging papules or nodules
  • Dermal contractures and ropelike elevation of the skin
  • Double-ended comedones

The axillae and the groin are the 2 areas most frequently affected. These regions are defined by anatomic borders and are called designated sites. Hidradenitis suppurativa is diagnosed if the patient has 1 of the following:

  • Active disease with 1 or more primary lesions in a designated site, plus a history of 3 or more discharging or painful lumps (not specified) in designated sites since age 10 years
  • Inactive disease with a history of 5 or more discharging or painful lumps (unspecified) in designated sites since age 10 years, in the absence of current primary lesions [4]

Other authors have based the diagnosis on a series of questions, as follows [5] :

  • Is there more than a single inflamed lesion?
  • Is the course chronic, with new and recurrent lesions?
  • Are the lesions bilateral?
  • Are the lesions located primarily in the milk line?


The Hurley clinical staging of hidradenitis suppurativa from 1989 is still relevant today; it has diagnostic value but is not suitable for monitoring the efficacy of interventions in clinical trials. [1] This staging is as follows:

  • First stage: Solitary/multiple, isolated abscess formation without scarring or sinus tracts
  • Second stage: Recurrent abscesses, single/multiple widely separated lesions, with sinus tract formation and cicatrization
  • Third stage: Diffuse/broad involvement or multiple interconnected sinus tracts/abscesses across the entire area

Dynamic staging Sartorius Score systems have been used for assessing differences in treatment effects. [6] Uniform outcome variables should take into account the known characteristics of hidradenitis suppurativa, including the following [6] :

  • Anatomic region involved (axilla, groin, genital, gluteal, or other inflammatory region left and/or right): 3 points per region involved
  • Number and scores of lesions (abscesses, nodules, fistulas, scars): 2 points for each nodule, 4 points for each fistula, 1 point for each scar, 1 point each for "other"
  • Longest distance between 2 relevant lesions (ie, nodules and fistulas, in each region, or size if only 1 lesion): Less than 5 cm, 2 points; less than 10 cm, 4 points; more than 10 cm, 8 points
  • Lesions clearly separated by normal skin in each region: If yes, 0 points; if no, 6 points

A recently developed six-stage physician global assessment (PGA) is defined as follows:

  • Clear: No inflammatory or noninflammatory nodules
  • Minimal: Only the presence of noninflammatory nodules
  • Mild: Fewer than five inflammatory nodules or one abscess or draining fistula and no inflammatory nodules
  • Moderate: Fewer than five inflammatory nodules or one abscess or draining fistula and one or more inflammatory nodules or 2-5 abscesses or draining fistulas and fewer than 10 inflammatory nodules
  • Severe: Two to five abscesses or draining fistulas and 10 or more inflammatory nodules
  • Very severe: More than five abscesses or draining fistulas

However, a Hurley severity grade‒relevant conservative and surgical treatment for hidradenitis suppurativa is recommended. [1, 7] In order to assess any treatment effectiveness, it is very important to standardize relevant endpoints. Defined as at least a 50% reduction in total abscess and inflammatory nodule count with no increase in abscess count and no increase in draining fistula count relative to baseline at week 12, the hidradenitis suppurativa clinical response (HiSCR) is currently the most appropriate clinical endpoint to assess treatment and effectiveness for hidradenitis suppurativa treatment. It does not contradict hidradenitis suppurativa response measured by the modified Sartorius Score or PGA, but rather represents a more sensitive measure of change in disease activity, resulting in a more accurate representation of patient response and treatment evaluation. The HiSCR does not take into account the size or severity of individual lesions and does not measure how treatment response affects a patient’s level of pain or quality of life. However, the threshold of 50% reduction in total abscess and inflammatory nodule count is the defined level that is clinically appropriate and meaningful to the patient regarding improvement in quality of life and pain level. [8]

Laboratory testing

The following laboratory tests may be helpful in the evaluation of hidradenitis suppurativa:

  • Complete blood count with differential and platelet counts (occasionally elevated white blood count)
  • Erythrocyte sedimentation rate (may be elevated)
  • C-reactive protein assay
  • Urinalysis
  • Serum multiphasic analysis with determination of the serum iron level and serum protein electrophoresis (possibly low serum iron levels, serum protein abnormalities)

Other studies that may be helpful include the following:

  • Bacteriologic analysis (eg, bacteriologic sampling and cultivation)
  • Immunochemistry for various cytokeratins and 6 desmosomal cadherins (ie, desmogleins [Dsgs] 1-3, desmocollins [Dscs] 1-3)
  • Histologic examination

Imaging studies

Ultrasonography of the hair follicles and dermal thickness in hidradenitis suppurativa patients may reveal abnormalities in the deep part of the follicle.

See Workup for more detail.


Medical management is recommended in early stages, whereas surgery should be performed after the formation of abscesses, fistulas, scars, and sinus tracts. [5]

Systemic treatment does not restore the skin’s original architecture; therefore, once the inflammation has been treated, epithelialized cysts and sinus tracts remain in the affected skin. [9]

Conservative treatment may include the following:

  • Local hygiene
  • Weight reduction in patients who are obese
  • Use of ordinary soaps and antiseptic and antiperspirant agents (eg, 6.25% aluminum chloride hexahydrate in absolute ethanol)
  • Application of warm compresses with sodium chloride solution or Burow solution
  • Wearing of loose-fitting clothing
  • Laser hair removal
  • Discontinuation of cigarette smoking
  • Medical anti-inflammatory or antiandrogen therapy (eg, oral or topical antibiotics, intralesional triamcinolone, spironolactone, finasteride)
  • Biological therapy

The following medications are used in the management of hidradenitis suppurativa:

  • Antibiotics (eg, tetracycline, doxycycline, minocycline, trimethoprim-sulfamethoxazole, clindamycin, erythromycin, dapsone)
  • Retinoids (eg, isotretinoin)
  • Corticosteroids (eg, triamcinolone, prednisolone, prednisone)
  • Antiandrogens (eg, cyproterone acetate, spironolactone)
  • Immunosuppressants (eg, adalimumab, infliximab, other biologic agents)
  • Estrogen derivatives (eg, ethinyl estradiol)
  • 5-Alpha-reductase inhibitors (eg, finasteride)


Surgery is most valuable in the chronic and recurrent stages of hidradenitis suppurativa. [5, 7] Wide surgical excision, with margins well beyond the clinical borders of activity, remains the most definitive surgical therapy. [5, 8, 9] However, although recurrence rates may be lower with aggressive surgery, recurrences often continue. [10, 11] After radical excision, the disease has been reported to recur in 33% of patients, [11] and it may be as high as 50% in the submammary region. [12]

More limited surgical intervention may include the following [13, 14, 15, 16] :

  • Drainage
  • Nd:YAG laser treatment of lesions
  • Exteriorization
  • Curettage
  • Electrocoagulation of the sinus tracts
  • Deroofing and skin-tissue-saving excision with electrosurgical peeling
  • Simple excision of the troublesome areas with direct closure
  • Reconstruction with skin grafting and negative-pressure wound healing therapy
  • Placement of local cutaneous flaps, musculocutaneous flaps, pedicled and free flaps, or skin grafts
  • Secondary-intention healing


Nonablative radiofrequency therapy can be used for patients with Harley stage I and II disease. [17]

See Treatment and Medication for more detail.



Hidradenitis suppurativa (HS) is a disorder of the terminal follicular epithelium in the apocrine gland–bearing skin. Hidradenitis suppurativa is characterized by comedolike follicular occlusion, chronic relapsing inflammation, mucopurulent discharge, and progressive scarring.



Hidradenitis suppurativa (HS) has traditionally been considered a disorder of the apocrine glands. Hidradenitis suppurativa was first described as a distinct entity in 1839, when Velpeau reported a patient with superficial abscess formation in the axillary, mammary, and perianal regions. [18] In 1854, Verneuil associated the suppurative process with the sweat glands, and the condition was given its current name. For many years, the condition was described as Verneuil disease, but it subsequently became known as hidradenitis suppurativa. Not having performed any histopathologic studies himself, Verneuil conceded that his conclusion was based purely on the characteristic distribution of the condition. [19]

In 1922, Schiefferdecker classified the sweat glands as eccrine and apocrine, and he subsequently localized hidradenitis suppurativa to the apocrine glands. [20] In 1939, Brunsting provided a detailed description of the histologic features of hidradenitis suppurativa. He observed the primary cellular reaction in the lumen of the apocrine glands and in the neighboring periglandular connective tissue. Detailing the clinical features of the disease, Brunsting highlighted its frequent association with acne. He noted that hidradenitis suppurativa, dissecting cellulitis of the scalp and the neck, and acne conglobata commonly occur in the same patient. He thought that the central pathogenetic event in all 3 conditions was a tendency for follicular hyperkeratinization with secondary bacterial infection. [21]

In 1956, Pillsbury et al combined acne conglobata, hidradenitis suppurativa, and dissecting cellulitis under the term follicular occlusion triad. [22] The only flaw in their concept was their focus on apocrine sweat gland involvement. In 1975, Plewig and Kligman added pilonidal sinus as another component to the ensemble, and they introduced the term acne tetrad. [23] Plewig and Kligman pointed out that hidradenitis suppurativa is a misnomer because of the lack of apocrine gland involvement, but they did not present a detailed explanation. In 1989, Plewig and Steger suggested the term acne inversa as an inclusive and accurate name for what was previously called the follicular occlusion triad, or follicular occlusion tetrad. [24] Eventually, hidradenitis suppurativa was accepted as an acneiform disorder that begins with follicular occlusion rather than an infection of the sweat glands. [25, 26]

Hidradenitis suppurativa is actually a defect of the follicular epithelium; therefore, there is a movement towards calling the disease acne inversa instead of hidradenitis suppurativa. The term acne inversa links the pathogenesis to acne and reflects the fact that it is an expression of follicular occlusion in localizations inverse to acne vulgaris. [27] However, hidradenitis suppurativa differs from acne in that no increase in sebaceous secretions is seen in hidradenitis suppurativa.



United States

In the United States, the prevalence of hidradenitis suppurativa appears to be 1-2% in the general population.


The prevalence of hidradenitis suppurativa appears to be 1% of the general population [28, 10] ; it was 4% in a group of young adults who were treated at a clinic for sexually transmitted diseases. [10] A 2008 study showed that the prevalence among persons aged 55 years and older was significantly lower than in younger age groups (0.5% vs 1.4%). [29] . Studies that provide prevalence or incidence estimations have been performed under different settings (hospital vs population-based) and in different periods. [28]


Most authors report no specific racial predilection. One report suggests an increased incidence is observed in blacks, possibly because blacks have a greater density of apocrine glands than whites. [12]


Although hidradenitis suppurativa is widely considered to occur more frequently in females than in males, with a ratio as high as 2-5:1, [4, 30] reports on sex prevalence are controversial. [4, 31, 32] . In fact, females were more likely to have a family history of hidradenitis suppurativa, and men had a tendency for more severe disease and associated severe acne. [32]

Active genitofemoral lesions occur significantly more often in females, whereas perianal involvement tends to be more common in males. No sex difference is seen in the axillary lesions. Comedones have been suggested as precursor lesions for hidradenitis suppurativa, and they appear to be equally distributed in both sexes and sites. [33]


The onset of hidradenitis suppurativa ranges from 11-50 years, with an average patient age of 23 years. [4] In less than 2% of patients, the disease appears before age 11 years. [34] In extremely rare cases, hidradenitis suppurativa occurs before puberty, but it has been suggested that a prepubertal onset is not uncommon in severely affected patients. [35, 36] or after menopause. [37]



Hidradenitis suppurativa is a chronic disabling disorder that relentlessly progresses, frequently causing keloids, contractures, and immobility.

The disorder has significant socioeconomic effects as well. Jemec et al documented, in the Danish population, an average of 2.7 lost work days per year due to hidradenitis suppurativa (overall workdays lost was 7.5). [30] The general self-reported level of health, which is well correlated with more objective parameters of morbidity, was also significantly worse among hidradenitis suppurativa patients than healthy control subjects. [30] The mean Dermatology Life Quality Index (DLQI) score for hidradenitis suppurativa is higher than for previously studied skin diseases, indicating significant morbidity for those affected. [4]



In general, hidradenitis suppurativa is a chronic disease, as underscored by the finding that 90% of patients in one large series still had active disease in the last year despite an average disease duration of nearly 19 years. [4]

The impression of a relentlessly progressive disorder may be explained by the finding that almost two thirds of patients acknowledged the existence of persistently painful boils that failed to heal. Possibly, new boils develop at an unchanged rate throughout the course of the disease, but some fail to subside in the usual manner and become chronic. [4]

With rare exceptions, surgical intervention is sufficient to stop the disease. [38] Shame, frustration, and despair may cause patients to delay radical surgical procedures.

No single treatment has shown overwhelmingly positive outcomes. [39]

Spontaneous resolution is rare. [7]

Specific factors appear to influence the prognosis. Larger excisions may offer a better outcome. Better results can be obtained by leaving wounds to secondary healing. Perianal surgery, axillary surgery, and older patient age are associated with lower recurrence rates, irrespective of the preoperative duration. [33]

The recurrence rate in patients treated with radical surgery varies considerably depending on the site affected; the highest rate is 50% in the submammary region. [12] An overall recurrence rate of 2.5% have been estimated after wide surgical excision, with a median postoperative follow-up of 36 months. [7]

The postoperative relapse risk is higher in women after surgery under general anaesthesia in severe hidradenitis suppurativa. [36]

If untreated, the disease causes significant morbidity, particularly in women and patients with moderate and severe disease who are more likely to experience a significant diagnostic delay (>2 y). [40]


Patient Education

Patients should be educated about the initial treatments, which include the following [15] (see Medical Care):

  • Practicing proper hygiene
  • Using soaps and antiseptic and antiperspirant agents
  • Using warm compresses
  • Wearing loose-fitting clothing
  • Smoking cessation

Patients who are obese should be educated about weight loss (see Diet). Additionally, patients should be educated about activities that may provide some relief of their condition [4] (see Activity). These activities include swimming, bathing, and avoiding smoking.

For patient education resources, see the Skin Conditions and Beauty Center. Also see the patient education article Boils.