Specialty Dermatology ICD-9-CM 705.83 | ICD-10 L73.2 DiseasesDB 5892 | |
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eMedicine emerg/259 med/2717 derm/892 Patient UK Hidradenitis suppurativa | ||
Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic skin disease characterized by clusters of abscesses or subcutaneous boil-like "infections" (often free of actual bacteria) that most commonly affects the underarms, under the breasts, inner thighs, groin, and buttocks. Outbreaks are painful and may persist for years with interspersed periods of inflammation, often culminating in sudden drainage of pus. This process often forms open wounds that do not heal and frequently leads to significant scarring.
Contents
- Terminology
- Causes
- Triggering factors
- Predisposing factors
- Stages
- Hurleys staging system
- Sartorius staging system
- Treatments
- Lifestyle
- Medication
- Surgery
- Laser hair removal
- Prognosis
- Potential complications
- History
- Other names
- References
Persistent lesions may lead to 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. Depression and pain are often seen with HS and can be difficult to manage. HS often goes undiagnosed for years due to embarrassment causing delay in seeking treatment.
HS flares may be triggered by emotional/erotic stress, sweating, hormonal changes, heat, and humidity, and the condition is exacerbated by friction from clothing. The disease is not contagious. Heredity is indicated among certain ethnic groups and is autoimmune in nature. Onset is most common in the late teens and early 20s. For unknown reasons, people with HS develop plugging of their apocrine glands.
Currently no cure nor any consistently effective treatment is known. Incision and drainage procedures may provide symptomatic relief. Carbon dioxide laser surgery may be an effective treatment with a low chance of recurrence. Lukewarm sitz baths can provide relief; gentle antiseptic skin cleansers and hydrogen peroxide assist in keeping affected areas free of bacteria. The number of people affected is not well established, but has been estimated as being between 1:24 (4.1%) and 1:600 (0.2%).
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 comedones and increased sebum production.
Causes
The cause of HS remains unknown and experts disagree over proposed causes.
Lesions occur in any body areas with hair follicles, although areas such as the axilla, groin, and perianal region are more commonly involved. This theory includes most of the following potentials indicators:
The historical understanding of the disease suggests dysfunctional apocrine glands or dysfunctional hair follicles, possibly triggered by a blocked gland, create inflammation, pain, and a swollen lesion.
Triggering factors
Several triggering factors should be taken into consideration:
Predisposing factors
Stages
HS presents itself in three stages. 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.
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:
Sartorius staging system
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:
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
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. Nearly a quarter of patients state that nothing relieves their symptoms. Possible treatments include the following:
Lifestyle
Medication
Surgery
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
The 1064 nanometer wavelength laser for hair removal aids in the treatment of HS. A randomized control study has shown improvement in HS lesions with the use of an Nd:YAG laser.
Prognosis
In stage III disease, fistulae 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 sepsis, but clinical data is still uncertain.
Potential complications
History
A surgeon from Paris, Velpeau described an unusual inflammatory process with formation of superficial axillary, submammary, and perianal abscesses in 1839. One of his colleagues also located in Paris, named Verneuil, coined the term hidrosadénite phlegmoneuse about 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 pathogenic association 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".
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.