Updates in Hidradenitis Suppurativa

Educational Objectives

The goal of this program is to improve the diagnosis and management of hidradenitis suppurativa (HS). After hearing and assimilating this program, the clinician will be better able to:

1. Identify the common clinical presentations of HS.
2. List common sites of involvement in HS.
3. Differentiate among Hurley stages in HS.

Summary

Hidradenitis suppurativa (HS): is a chronic inflammatory skin condition characterized by painful nodules, abscesses, dermal tunnels, and scarring; it has an intermittent waxing and waning course, primarily affecting skin folds, eg, armpits, groin, buttocks

Epidemiology: HS is more common in women than in men (3:1), and it disproportionately affects Black Americans and marginalized groups; pain is the primary symptom of HS, which has a bimodal age of onset, peaking at ≈16 yr of age (primarily in women) and ≈40 to 45 yr of age (in men and women); since HS often develops during adolescence, it becomes a chronic condition that impacts individuals for a significant portion of their lives, affecting school attendance, work productivity, and income potential; moderate and severe forms of HS significantly diminish quality of life; data on HS during pregnancy is limited, making it difficult to predict how the condition may change; while most women report postpartum flares, a concerning number of HS patients (≈50%) mistakenly believe they must stop all HS medications during pregnancy for safety reasons; women with HS are at an increased risk for spontaneous abortion, cesarean delivery (C-section), gestational diabetes, and hypertension; wound healing after C-section may be affected, with an increased risk for postpartum infection; breastfeeding may also be challenging because of HS lesions on the breasts or other areas that complicate positioning and comfort; shared decision-making regarding childbirth and breastfeeding is important for both maternal and infant health

Diagnosis: the average diagnostic delay reported in the literature is 7 to 10 yr; a worldwide survey indicated that ≈66% of patients consulted a clinician ≥5 times prior to diagnosis; the diagnosis of HS is primarily clinical

Criteria: 1) typical lesions (inflammatory nodules, abscesses, papules, pustules, and dermal tunnels), 2) typical distribution (axilla, inframammary folds, inguinal folds, and anogenital region), and 3) chronicity (≥2 episodes ≤6 mo); secondary criteria (family history, absence of cultured pathogens at lesion sites) are helpful but not required; referral to dermatology is important for early and aggressive treatment, particularly with medications

Strategy for managing HS: the goal is to prevent and reduce functional limitations, ideally avoiding scarring and disfigurement; historically, HS was treated primarily with surgery, unlike other inflammatory skin conditions; currently, treatment involves a 2-step process, ie, first, controlling the inflammation, and second, removing any irreversibly damaged (fibrotic) tissue

Pathogenesis: the accumulation of a lymphocytic infiltrate around the hair follicle leads to the formation of a keratin plug; this plug traps microbes and keratin, causing pressure, follicular rupture, and the formation of tunnels in the dermis, which results in a robust inflammatory response; HS flares in women often occur premenstrually, suggesting a hormonal component; treatments target microbes, hormonal fluctuations, and immune dysregulation

Staging: Hurley stage 1 involves nodules and abscesses (with or without scarring); stage 2 includes dermal tunnels, and stage 3 represents the presence of interconnected tunnels; early intervention, ideally between stages 1 and 2 before extensive tunneling and scarring develops, offers the best opportunity for aggressive management with biologics and immunomodulators to alter the disease trajectory

Medical management: often begins with broad-spectrum antibiotics because of the polymicrobial nature of HS lesions; topical clindamycin is used for mild cases; severe cases are treated with long courses of clindamycin and rifampin, or a combination of rifampin, moxifloxacin, and metronidazole (for 6 wk); antiseptic washes are used by patients with minimal evidence supporting their efficacy; specific antibiotic recommendations exist for pregnant and breastfeeding patients, with some deemed safe (eg, cephalexin, azithromycin) and others should be avoided; hormonal therapies, eg, spironolactone are used for patients with follicular involvement and polycystic ovarian syndrome; combined oral contraceptives are used; finasteride may be used in men; progestin-only contraceptives and testosterone therapy may worsen HS and are generally avoided; metformin is sometimes used, although its effectiveness is debated; both spironolactone and metformin are considered safe for breastfeeding; doxycycline must be avoided; oral contraceptives are generally safe and potentially beneficial for HS, including during breastfeeding, although they may reduce milk production

Biologics: are considered when scarring begins, aiming to prevent irreversible damage; tumor necrosis factor (TNF) inhibitors are approved by the US Food and Drug Administration (FDA) for HS; adalimumab was the first, showing significant improvement (≥50% reduction in inflammatory nodules and abscesses without worsening tunnels or new abscesses) in pivotal trials; it works best when started early in the disease course; if a patient does not respond to adalimumab therapy, a high-dose, high-frequency regimen of infliximab is recommended (≤10 mg/kg every 4 wk for severe cases); methotrexate (or azathioprine for pregnant individuals) is often coadministered with infliximab (a mouse chimeric antibody) to prevent antidrug antibody formation; TNF inhibitors may increase the risk for upper respiratory and skin infections, particularly in patients with comorbidities, eg, pulmonary, cardiovascular disease, and diabetes; older adults have an increased risk for malignancy

Interleukin 17A (IL-17A) inhibitors: secukinumab was recently approved by the FDA for HS; the approval for bimekizumab is anticipated shortly; evidence suggests that 45% to 50% of participants achieve HS clinical response with IL-17 inhibition, significantly more than placebo; these medications also have a better safety profile than TNF inhibitors; there is an increased risk for fungal (Candida) infections; the risk is lower for patients on lower doses (4 wk vs 2 wk); IL-17A inhibitors should be avoided in patients with inflammatory bowel disease (IBD) or those with a family history of IBD; deaths because of cardiovascular events and gastrointestinal hemorrhage have been reported in trials

Use of biologics in pregnant and breastfeeding women: requires collaboration with obstetricians and gynecologists; most medications cross the placenta in the third trimester, and some pass into breast milk; patients should establish care with a pediatrician before delivery to discuss vaccination schedule adjustments (live vaccines should be delayed ≤6 mo after the last TNF inhibitor exposure); nonlive vaccines can be given on schedule; adalimumab has the most safety and efficacy data in HS, but infliximab and secukinumab are often continued through pregnancy; certolizumab is a TNF inhibitor that does not cross the placenta, but its efficacy is questionable; prednisone and intralesional triamcinolone are limited to acute flares; cyclosporine may be used during pregnancy; HS treatment involves layered therapies; patients may be on systemic antibiotics, hormonal therapies, and a biologic concurrently; severe cases may require dual biologics or a biologic combined with a small molecule inhibitor (eg, Janus kinase inhibitor)

Surgical management: once inflammation is controlled (no new lesions), treatment focuses on removing irreversibly damaged tissue; for single tunnels (Hurley stage 2), deroofing is performed as an outpatient procedure under local anesthesia; the tunnel roof is removed, the base cauterized, and the wound dressed; healing occurs by secondary intention ≤6 wk; extensive stage 3 disease requires wide local excision under general anesthesia, often performed by general or plastic surgeons; biologic regimens should be maintained perioperatively and postoperatively to prevent the formation of new lesions

Readings

Amat-Samaranch V, Agut-Busquet E, Vilarrasa E, et al. New perspectives on the treatment of hidradenitis suppurativa. Ther Adv Chronic Dis. 2021;12:20406223211055920. doi:10.1177/20406223211055920; Collier EK, Seivright JR, Shi VY, et al. Pregnancy and breastfeeding in hidradenitis suppurativa: a review of medication safety. Dermatol Ther. 2021;34(1):e14674. doi:10.1111/dth.14674; Dagenet CB, De DR, Shih T, et al. Hurley staging training for hidradenitis suppurativa patients. Skin Appendage Disord. 2024;10(6):524-27. doi:10.1159/000539746; Krueger JG, Frew J, Jemec GBE, et al. Hidradenitis suppurativa: new insights into disease mechanisms and an evolving treatment landscape. Br J Dermatol. 2024;190(2):149-62. doi:10.1093/bjd/ljad345; Seivright JR, Villa NM, Grogan T, et al. Impact of pregnancy on hidradenitis suppurativa disease course: a systematic review and meta-analysis. Dermatology. 2022;238(2):260-66. doi:10.1159/000517283; Shih T, Lee K, Grogan T, et al. Infliximab in hidradenitis suppurativa: a systematic review and meta-analysis. Dermatol Ther. 2022;35(9):e15691. doi:10.1111/dth.15691.

Disclosures

For this program, the following relevant financial relationships were disclosed and mitigated to ensure that no commercial bias has been inserted into this content: Dr. Naik is a consultant for Abbvie, Medscape, Novartis, Sonoma Biotherapeutics, and UCB; and is a stockholder with Radera. Members of the planning committee reported nothing relevant to disclose. Dr. Naik's lecture includes off-label or investigational use of clindamycin, rifampin, moxifloxacin, metronidazole, antiseptic washes, antibiotics, hormonal therapies, metformin, spironolactone, and oral contraceptives in treatment of hidradenitis suppurativa.

Acknowledgements

Dr. Naik was recorded at Obstetrics and Gynecology Update: What Does the Evidence Tell Us?, held September 25-27, 2024, in San Francisco, CA, and presented by the University of California, San Francisco. For information on upcoming CME activities from this presenter, please visit ObGynUpdate.ucsf.edu. Audio Digest thanks the speakers and the University of California, San Francisco, for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 1.00 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 1.00 CE contact hours.

Lecture ID:

OB720601

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.