SAN DIEGO — In light of major advances over the past 6 years, it’s past time to update guidelines to treat hidradenitis suppurativa (HS), a dermatologist told colleagues at the 2025 CalDerm-Pacific Dermatologic Association (PDA) Joint Meeting.

“The 2019 North American guidelines are really outdated,” Jennifer Hsiao, MD, associate clinical professor of dermatology and director of the HS clinic at the University of Southern California, Los Angeles, said at the meeting. “Two of our three FDA-approved therapies right now are IL [interleukin]-17 inhibitors, but they’re not even in the algorithm. You see a lot of things that are missing.” (The guidelines were published in two parts, one that included recommendations on diagnosis and evaluation of patients and the second on topical, intralesional, and systemic management.)

To make matters worse, she said, “Insurance pushes back when we try to get meds for a patient” when they are not in the guidelines.

What to do? To help dermatologists understand the evolution of gold-standard HS care, Hsiao and colleagues recently published an updated algorithm of HS management in the American Journal of Clinical Dermatology. In the paper, the experts say, “A multimodal approach and treatment stacking of both medical and surgical interventions are essential to optimize management of HS given its proposed multifactorial etiology,” defining treatment stacking as “layering of therapeutic interventions from multiple therapeutic categories.” Interventions include topical therapies, systemic antibiotics, hormonal and metabolic treatments, biologics, pain management, wound care, lifestyle modifications, and surgery.

At the meeting, Hsiao offered the following tips regarding different aspects of HS care:

Severity Assessment

Identify moderate HS without using clinical trial criteria that define severity based on multiple abscesses and inflammatory nodules, Hsiao recommended.

She highlighted the Physician Global Assessment Tool for HS. “Basically, having one abscess and one inflammatory nodule means you have moderate HS disease,” she said. “Nowhere does it mention that you have to have a scar or you have to have a tunnel. And I’m really glad about that because our goal should be to try to prevent tissue destruction, prevent tunnels, and prevent scars.”

The definition of disease severity is important, Hsiao noted, because patients with moderate-to-severe HS qualify for biologics. “By starting earlier, our medications will have a better chance of having higher efficacy.”

Therapy Buckets

Hsiao recommends grouping treatment strategies into topical, antibiotic, hormonal, metabolic, and biologic options.

Topical therapy: Topical ruxolitinib, a JAK inhibitor, is currently being evaluated for HS in phase 3 trials, and if approved, “would be the first indication we have for milder HS,” she noted.

Antibiotics: Many options are available, including doxycycline, amoxicillin/clavulanic acid, and clindamycin. “Antibiotics are not for long-term therapeutic management. I use them in two ways,” Hsiao said. One is for 1 or 2 weeks of flare management, where patients keep a bottle of amoxicillin/clavulanic acid or doxycycline at home for “when they feel like they’re flaring,” she said. “Or I use them as a bridge therapy while I’m starting a biologic, maybe for 3 months, to try to cool things down faster, to let their long-term management kick in.”

Hormonal therapies: Spironolactone, finasteride, and estrogen-containing combined oral contraceptives remain valuable tools. The 2025 algorithm notes that the 2019 guidelines recommended these therapies, plus metformin, “for females with mild-to-moderate disease or as adjunctive treatment for severe disease in patients with premenstrual flares or polycystic ovarian syndrome (PCOS).” Metformin and finasteride, the algorithm adds, “are options for male patients, as they are widely used in other medical conditions, including diabetes and hair loss, respectively.”

Metabolic therapies: GLP-1 receptor agonists are “certainly a hot topic for HS,” Hsiao said, because they can improve metabolic dysfunction and cardiac risk, though she cautioned that current evidence — including a recently published study — is limited to retrospective cohorts. “A lot of these patients are on concomitant medications, so it’s a little bit difficult to tell if it’s the GLP-1 vs a synergistic effect.”

Retinoids: “Acitretin has more data than isotretinoin. Start low and go slow because patients can flare,” but be cautious of risks in women of child-bearing age, she said. The algorithm highlights a recent study of 62 patients with HS treated with acitretin, which “demonstrated significant improvement in International HS Severity Score System (IHS4) scores” in male patients but not in female patients.

Biologics: Those with the most evidence for HS are adalimumab, secukinumab, and bimekizumab, which she said are “all first-line treatments,” and infliximab plus JAK inhibitors such as upadacitinib. If treatment with adalimumab, bimekizumab, or secukinumab “is found to be inadequate, one can be switched for the other,” the algorithm states, adding: “Alternatively, therapy can be escalated to infliximab. In severe cases, it may be beneficial to start with infliximab (if insurance permits) with plans to de-escalate to adalimumab or secukinumab once disease is controlled.”

The algorithm adds, “To mitigate the development of antidrug antibodies and ensure treatment endurance, the initiation of infliximab may be accompanied by the use of methotrexate or azathioprine, and antibody and drug levels may be monitored.”

Treatment Flexibility

Consider updosing adalimumab, secukinumab, and bimekizumab over time in some cases, Hsiao said. As an example, someone on adalimumab every 2 weeks who says he or she is doing pretty well but tends to experience more disease activity and inflammation shortly before the next injection would be a good candidate for updosing, she added, noting that more than half of her adalimumab patients with HS on adalimumab are escalated to weekly dosing.

She also described combining advanced agents such as two biologics or a biologic plus a JAK inhibitor. “The first time I thought about it, I was very worried. What about safety? The good news is that in the IBD [inflammatory bowel disease] and rheumatoid arthritis literature, there’s data for dual biologic therapy as well as biologic plus JAK inhibitor therapy.” Currently, there are no major safety signals for combination therapy, although treatment with a TNF inhibitor plus an IL-1 blocker should be avoided.

As for treatments in the pipeline, Hsiao noted that the JAK inhibitor povorcitinib met its primary endpoints in phase 3 trials. “Hopefully by next year, we’ll get povorcitinib on the market, which would be a new mechanism of action for HS, and…it would be a pill, not an injection.”

Hsiao is on the board of directors of the HS Foundation and disclosed having relationships with AbbVie, Aclaris, AstraZeneca, Boehringer Ingelheim, Galderma, Incyte, Novartis, Pfizer, Regeneron, Sanofi, and UCB.