Synonyms
Subdivisions
General Discussion
Hidradenitis suppurativa (HS) is a chronic, and often debilitating, skin condition in which painful, inflamed lesions form within the skin. These lesions may present as large cysts, inflamed nodules, purulent draining sinus tracts (collections of pus under the skin which drain via a small opening) , or large open comedones (blackheads) (1). Lesions form commonly in skin folds (intertriginous locations) with numerous hair follicles and where skin experiences a high degree of friction, such as the underarms, breasts, buttocks, inner thighs, and groin. HS can also form less commonly near the ears, around the belly button, face, neck, or back. When lesions become irritated and inflamed, they often drain malodorous, pus-like fluid. Lesions tend to heal slowly, recur, and eventually scar the skin through the formation of tunnels, called sinus tracts, under the skin. These scars may eventually lead to restriction of movement in the affected areas and cause overall destruction of normal skin architecture (2). As such, this condition might affect sexual function and sexual health overall given their associated locations in the underarms, breasts, buttocks, inner thighs, and groin.
Signs & Symptoms
Causes
On a cellular level, when hair follicles become clogged with sweat and keratin (the protein that makes up our skin cells) they distend to the point of bursting. When released into the deeper dermal tissue, keratin is considered a foreign material, and then a profound inflammatory response is incited leading to pain, scarring, and drainage.
While the exact etiology of HS is unknown, there is now a greater understanding of a genetic predisposition towards HS, which becomes activated with secondary inflammatory insults such as smoking, poor glycemic (blood sugar) control, and hormonal fluctuations. Recent research suggests that HS may have autoimmune involvement, with patients affected by HS developing antibodies to their own tissues. The presence of antinuclear antibodies, which are commonly associated with autoimmune diseases like systemic lupus erythematosus, have been detected in some HS patients. Additionally, anti-citrullinated protein antibodies, which are commonly associated with rheumatoid arthritis, have also been found in HS patients (1).
Affected Populations
Most patients develop HS between puberty and age 40, with very low incidence of onset before puberty. In the United States, data has shown higher diagnosis rates for patients of African American, Hispanic, and biracial descent compared to White patients. HS is more commonly seen in females than males. A notable decrease in the severity of HS during pregnancy and after the start of menopause underscores the importance hormones play in this disease entity (1).
Diagnosis
The average time to receive a diagnosis of HS is 7 years as it can often be mistaken for severe pimples, acne, or other conditions. HS can be mild, moderate, or severe, resulting in different symptoms and signs used for diagnosis. The Hurley staging system can be used to classify the disease and guide treatment. Hurley Stage 1 involves abscesses that lack tunnels and scars. Hurley Stage 2 involves recurrent abscesses that have tunnels and scars, and the lesions may be single or multiple. The last stage is Hurley Stage 3 which differs from Stage 2 with its more pronounced and extensive scarring and diffuse involvement of the skin. In Hurley Stage 3, the lesions diffusely involve the skin, there are extensive abscesses and sinus tracts, and significant scarring. Timely, accurate diagnosis of HS is important for managing symptoms and reducing the development of new and rapidly progressive lesions (4). A thorough medical history and complete skin examination is imperative. While HS lesions are inflammatory, rarely, they may be superinfected and bacterial culture may be necessary (2). Finally, squamous cell carcinoma may develop in chronically inflamed, actively draining skin. For any firm, painful, rapidly growing nodules occurring in long-standing HS lesions, there should be a low threshold for skin biopsy with concern for this malignancy.
Standard Therapies
The treatment of HS depends on severity, divided by Hurley stages, and patient symptoms. Patient education is imperative as lifestyle modifications such as smoking cessation and weight loss can make a profound impact. Further, years of misdiagnosis results in mistrust of the medical system and healthcare providers. The physical appearance and malodor can have profound effects on the patients social, emotional, sexual, and mental health. All of these must be addressed, particularly at initial patient visits.
Stage 1 can be treated with topical clindamycin, corticosteroids, topical resorcinol, or oral tetracyclines. Stage 2 can be treated with oral tetracyclines, combination therapy with clindamycin and rifampin, and other antibiotics. Wide excision is typically used in Hurley Stage 3 disease (6).
The mainstays of medical management include topical and oral antibiotics, antiseptic washes, birth control, retinoids, steroids, immunosuppressive injections, or de-roofing surgery (2).
Topical antiseptic medications such as benzoyl peroxide and chlorhexidine gluconate are often recommended for maintenance therapy. Topical and oral antibiotics such as doxycycline, clindamycin, and rifampin are prescribed for both their antibiotic and anti-inflammatory properties.
In cases of hormonally-exacerbated HS manifesting as premenstrual or menstrually-related flares, combination oral contraceptives or spironolactone may be considered.
Retinoids have shown modest benefit for HS and are contraindicated in pregnancy. The use of topical and oral steroids is typically limited but may be considered for severe, painful flares. Intralesional steroids are commonly utilized to expedite resolution of isolated, painful lesions (5).
Severe cases of HS may require the use of biologic medications such as adalimumab, infliximab, and secukinumab which was recently approved by the FDA for this indication.
CO2 lasers were among the first tools to be used to treat hidradenitis suppurativa and used for deroofing and excision of sinus tracts with minimal bleeding. Additionally, non-ablative lasers and light therapies, such as Nd (1,064 nm), Alexandrite (755 nm), and intense pulse light, have shown benefits by targeting and destroying the hair follicle, which is key to the HS pathogenesis. Both lasers and intense pulsed light target melanin found in hair follicles–leading to their destruction–and water molecules in the skin. Once the hair follicle is damaged, it cannot produce hair or produces much finer, less noticeable hair.
Investigational Therapies
Support Available
While HS may have severe physical manifestations, patients may also feel socially isolated and stigmatized by their disease which causes significant mental and emotional burden. The International Association of Hidradenitis Suppurativa Network (IAHSN) is an organization based in the United States dedicated to creating a community for patients affected by HS. IAHSN creates and disseminates education materials, connects patients to dermatologists and other providers, supports patient health plans, and creates space for all affected by HS through hosting events and advocacy initiatives (3).
References
- "Hidradenitis Suppurativa Causes." American Academy of Dermatology, American Academy of Dermatology, https://www.aad.org/public/diseases/a-z/hidradenitis-suppurativa-causes. Accessed 28 July 2024.
- Hidradenitis Suppurativa (HS): Diagnosis, Treatment, and Steps to Take." National Institute of Arthritis and Musculoskeletal and Skin Diseases, U.S. Department of Health and Human Services, https://www.niams.nih.gov/health-topics/hidradenitis-suppurativa-hs/diagnosis-treatment-and-steps-to-take. Accessed 28 July 2024.
- "Complications of Hidradenitis Suppurativa." International Alliance of Hidradenitis Suppurativa Networks, https://www.iahsn.org/hsdisease/complications-hs.html. Accessed 28 July 2024.
- Kokolakis et. al. "Delayed Diagnosis of Hidradenitis Suppurativa and Its Impact on Disease Outcome." Dermatology Research and Practice, vol. 2024, Article ID 113983, 2024. Karger Publishers, https://karger.com/drm/article/236/5/421/113983/Delayed-Diagnosis-of-Hidradenitis-Suppurativa-and. Accessed 28 July 2024.
- Fragoso, N.M., Masson, R., Gillenwater, T.J, Shi, V.Y. & J.L. Hsiao. Emerging Treatments and the Clinical Trial Landscape for Hidradenitis Suppurativa—Part II: Procedural and Wound Care Therapies. Dermatol Ther (Heidelb)13, 1699–1720 (2023). https://doi.org/10.1007/s13555-023-00957-5
- Ballard, Karen, and Victoria L. Shuman. Hidradenitis Suppurativa. StatPearls, updated 6 May 2024, StatPearls Publishing, https://www.ncbi.nlm.nih.gov/books/NBK534867/. Accessed 28 July 2024.
