Hidradenitis suppurativa

Hidradenitis suppurativa (HS), sometimes known as acne inversa or Verneuil's disease, is a long-term

If mild cases of HS are included, then the estimate of its frequency is from 1–4% of the population.[2]^[3] Women are three times more likely to be diagnosed with it than men.^[2] Onset is typically in young adulthood and may become less common after 50 years old.^[2] It was first described between 1833 and 1839 by French anatomist Alfred Velpeau.^[1][12]

Terminology

Although hidradenitis suppurativa is often referred to as acne inversa, it is not a form of acne, and lacks the core defining features of acne such as the presence of closed

The exact cause of hidradenitis suppurativa remains unknown,[11]^[14] and there has, in the recent past, been notable disagreement among experts in this regard.^[15] The condition, however, likely stems from both genetic and environmental causes.^[3] Specifically, an immune-mediated pathology has been proposed,^[11] although environmental factors have not been ruled out.^[3]

Lesions will occur in any body areas with hair follicles,^[15] and/or sweat glands,^[16] although areas such as the axilla, groin, and perineal region are more commonly involved. This theory includes most of these potential indicators:^[17]

• Post-pubescent individuals^[18]
• Blocked hair follicles or blocked apocrine sweat glands
• Excessive sweating
• Androgen dysfunction
• Genetic disorders that alter cell structure

The historical understanding of the disease suggests dysfunctional apocrine glands^[19] or dysfunctional hair follicles,^[20] possibly triggered by a blocked gland, which creates inflammation, pain, and a swollen lesion.

Triggering factors

Several triggering factors should be taken into consideration:

• skin maceration
  .
• Tight clothing,^[21] and clothing made of heavy, nonbreathable materials^[23]
• depilation products, shaving of the affected area – their association with HS is still an ongoing debate among researchers.^[24]
• Drugs, in particular oral contraceptive pills,^[25] cigarette smoking,^[26][27] and lithium.^[28]
• Hot and especially humid climates.^[29]
• Stress^[27]

Predisposing factors

• autosomal dominant inheritance pattern has been proposed.^[30]
• hormones.^[31] Women often have outbreaks before their menstrual period and after pregnancy; HS severity usually decreases during pregnancy and after menopause
  .

Early diagnosis is essential in avoiding tissue damage. However HS is often misdiagnosed or diagnosed late due to healthcare professionals not being aware of the condition or people not consulting with a physician.[34]^[35] Globally, the diagnosis is delayed more than 7 years in average after symptoms appear. This is much longer than with other skin conditions.^[36]

Stages

Hidradenitis suppurativa presents itself in three stages.^[19][38] Due to the large spectrum of clinical severity and the severe impact on quality of life, a reliable method for evaluating HS severity is needed.^{[citation needed]}

Hurley's staging system

Hurley's staging system was the first classification system proposed, and is still in use for the classification of patients with skin diseases (i.e.,

The Sartorius 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:[40]

• Anatomic
  regions involved (axilla, groin gluteal, or other region or inframammary region left or right)
• Number and types of
  fistulas
  or sinuses, 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., if all lesions are 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.^[41]

Treatment

Treatment depends upon presentation and severity of the disease. Due to the poorly studied nature of the disease, the effectiveness of drugs and therapies were unclear.^[42] Clear and sensitive communication from health care professionals, social and psychological interventions can help managing the emotional impact of the condition and aid necessary lifestyle changes.^[34][35] In May 2023, the European Commission (EC) approved Cosentyx (secukinumab) for active moderate to severe hidradenitis suppurativa in adults.^[43]

Other possible treatments include the following:

Cryotherapy

Cryotherapy has demonstrated efficacy against the disease, with 88% of persistent lesions resolving in a clinical trial of 23 patients.^[44]

Lifestyle

Warm baths may be tried in those with mild disease.^[4] Weight loss and the cessation of smoking are also recommended.^[2]

Medication

• Antibiotics: taken by mouth, 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. Popular antibiotics also include tetracycline and minocycline.^[45] Topical clindamycin has been shown to have an effect in double-blind placebo controlled studies.^[46] In a retrospective review and telephone survey, intravenous ertapenem therapy showed clinical improvement with 80.3% of subjects reporting medium to high satisfaction and 90.8% would recommend ertapenem to other patients.^[47]
• 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.
• quality of available evidence is low and does not presently allow for robust evidence-based recommendations.^[48][49]
• TNF-alpha) drugs such as infliximab, and etanercept^[51] This use of these drugs is not currently Food and Drug Administration
  (FDA) approved and is somewhat controversial, so may not be covered by insurance.
• TNF inhibitor: Studies have supported that various TNF inhibitors have a positive effect on HS lesions.^[52] Specifically adalimumab at weekly intervals is useful.^[53] Adalimumab is the only medication approved by the FDA for the treatment of HS as of 2021.
• Topical
  acne vulgaris. Individuals affected by HS who responded to isotretinoin treatment tended to have milder cases of the condition.^[54]
• Zinc and Nicotinamide, at doses of 90 mg and 30 mg respectively, have shown efficacy against mild to moderate hidradenitis suppurativa in a controlled retrospective clinical trial.^[55]

Surgery

When the process becomes chronic, wide surgical excision is the procedure of choice.

Wounds in the affected area do not heal by

infections, amyloidosis, and arthropathy. Stage III complications have been known to lead to sepsis, but clinical data are still uncertain.

• axillae due to fibrosis and scarring occur. Severe lymphedema
  may develop in the lower limbs.
• Local and systemic
  infections (meningitis, bronchitis, pneumonia
  , etc.), are seen, which may even progress to sepsis.
• higher risk for
  diabetes mellitus^[61]
• Interstitial keratitis
• Anal, rectal, or urethral
  fistulae^[62]
• Normochromic or hypochromic anemia^[63]
• People with HS may be at increased risk for autoimmune disorders including ankylosing spondylitis, rheumatoid arthritis, and psoriatic arthritis.^[64]
• tumors
  are usually highly aggressive.
• Tumors of the
  oral cavity, and liver cancer^[66]
• Hypoproteinemia and amyloidosis, which can lead to kidney failure and death^[67]
• Seronegative and usually asymmetric
  polyarthralgia syndrome^[68]

HS is a painful and socially isolating condition which leads to a negative impact on mental health as well. 21% of people with HS have depression and 12% have anxiety.[69] People with HS also have a higher risk of attempting suicide.^[70]

Epidemiology

Prevalence

Estimates of the prevalence of HS vary worldwide and there is no accepted generalization. In the USA, the prevalence is estimated to be 0.1% while in Europe it is thought to be 1% or more.^[70]

Gender

In North America and Europe, women are three times more likely to have HS. However, in South Korea, men are twice as likely to have HS.^[70]

Age

HS is the most prevalent in people in their 40s and 50s.^[70]

History

• From 1833 to 1839, in a series of three publications, Velpeau identified and described a disease now known as hidradenitis suppurativa.^[71]
• In 1854, Verneuil described hidradenitis suppurativa as hidrosadénite Phlegmoneuse. This is how HS obtained its alternate name "Verneuil's disease".^[72]
• In 1922, Schiefferdecker hypothesized a
  pathogenic link between "acne inversa" and human sweat glands.^[73]
• In 1956, Pillsbury et al.[74] coined the term follicular occlusion triad for the common association of hidradenitis suppurativa, acne conglobata and dissecting cellulitis of the scalp. Modern clinical research still employs Pillsbury's terminology for these conditions' descriptions.^[75]
• 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".^[76]
  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.^[77]

A surgeon from Paris, Velpeau described an unusual inflammatory process with formation of superficial

Other names

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.^[38]

• Acne conglobata – not really a synonym – this is a similar process, but in classic acne areas of chest and back
• Acne inversa – a proposed new term^[78][79] which has not gained widespread favor.^[80]
• Apocrine acne – an outdated term based on the disproven^{[citation needed]} concept that apocrine glands are primarily involved, though many do have apocrine gland infection
• Apocrinitis – another outdated term based on the same thesis
• Fox-den disease – a term not used in medical literature, based on the deep fox den–like sinuses
• Hidradenitis supportiva – a misspelling
• Pyodermia fistulans significa – now considered archaic
• Verneuil's disease – recognizing the surgeon whose name is most often associated with the disorder as a result of his 1854–1865 studies^[81]

Histology

Society and culture

Experiences of people with HS

HS can have a strong negative impact on people's lives, as well as physical and mental health. People with HS often feel stigmatised and embarrassed by their condition. Many try to hide the symptoms which can lead to impaired relationships and social isolation. A multidisciplinary approach by healthcare professionals, social support networks and psychological interventions can contribute to a better quality of life.^[34][35] Compared to other skin diseases, HS has one of the highest Dermatology Life Quality Index (DLQI) scores.^[84]

References