Welcome back, DERM Community.
Last week we looked at the skin signs of diabetes, starting with acanthosis nigricans: the darkened neck that patients are told to scrub harder.
This week's disease gets the same bad advice…
Hidradenitis suppurativa (HS) is blamed on hygiene, drained like a boil, and keeps getting a different name for years.
The two issues may describe the same patient. HS carries its own elevated risk of type 2 diabetes, and it shows up in the same skin folds.
In this issue: five mistakes that delay the diagnosis
Calling it a boil
Treating every flare as a one-off
Blaming hygiene, shaving, or weight
Treating the skin and missing the rest
Referring too late
The patient you have already seen
The numbers behind the delay:
Prevalence: roughly 1% of people, with population estimates ranging from 0.1% to 4% depending on how it is counted
Time to diagnosis: 7 to 10 years on average from first symptom
Specialties consulted: more than three for the typical patient, most often primary care, dermatology, surgery, and gynecology
Misdiagnoses collected: more than three
That delay is not cosmetic. Longer time to diagnosis correlates with worse disease severity and more comorbidities at the point of diagnosis.
In a 2014 US claims study of over 16,000 HS patients, almost 16% were hospitalized over 3 years and more than a quarter were seen in the emergency department. This is a disease that starts in the exam room and, untreated, ends up in the ED.
Five mistakes keep the clock running.
Mistake 1: Calling it a boil
The short version: HS is a clinical diagnosis built on recurrence in a typical site, and it is available at the first visit.
Mechanism
HS is not primarily an infection. It is a chronic inflammatory disease of the hair follicle.
Follicular occlusion and rupture drive the inflammation
The resulting nodules and abscesses are frequently sterile on culture
Bacteria are bystanders more often than they are cause
That is why "recurrent furunculosis" keeps recurring: the antibiotic treats the wrong problem.
Evidence
The modified Dessau criteria used in the Australasian guidelines define HS by three things:
Typical lesions: nodules, abscesses, tunnels, double-ended comedones
Typical sites: axillae, groin, inframammary folds, buttocks, perineum
Recurrence: two or more episodes within 6 months
No lab test or imaging is required. The diagnosis is clinical, and it is available at the first visit if you ask the right question.
Practical tip
When a patient presents with an "abscess" in a fold, ask two things before you reach for the scalpel:
"Have you had one of these before?"
"Where else have you had them?"
A yes to either, plus a typical site, moves HS to the top of the differential. Document Hurley stage at diagnosis:
Hurley stage | Findings |
|---|---|
I | Nodules or abscesses without tunnels or scarring |
II | Draining tunnels and scarring added |
III | Diffuse involvement with interconnected tunnels across the region |
Mistake 2: Treating every flare as a one-off
The short version: drainage and 10 day antibiotic courses do not modify the disease. Treat in 12 week courses with a defined success measure.
Mechanism
Incision and drainage relieves pressure for days and the lesion refills
Repeated 7 to 10 day antibiotic courses give the same short arc: brief improvement, no disease modification, cumulative resistance
Neither addresses the inflammatory process, and both teach the patient that this is something to endure rather than manage.
Evidence
The 2019 North American guidelines (US and Canadian HS Foundations) recommend:
Acute lesions: no routine I&D unless there is a large, fluctuant fluid collection
Flares: intralesional triamcinolone as the office procedure
Maintenance, mild to moderate disease: oral tetracyclines as first-line
Maintenance, more severe disease: clindamycin plus rifampin as an option
Duration: 12 week courses for both regimens rather than short bursts
A prospective European cohort found no significant difference in response between tetracyclines and clindamycin plus rifampin, which supports starting with the simpler regimen.
Practical tip
Stop prescribing in 10 day increments.
Start doxycycline 100 mg twice daily for 12 weeks
Set a return visit at the end of that window with a defined success measure (fewer new lesions, less pain, no new tunnels)
Add topical clindamycin 1% for mild disease
If you have intralesional triamcinolone in the office, a small injection into a hot nodule beats a scalpel for most flares
Reserve I&D for a tense, fluctuant abscess
Mistake 3: Blaming hygiene, shaving, or weight
The short version: explain the disease model first and the modifiable factors second. Shame is one of the reasons patients stop coming in.
Mechanism
Three things HS is not:
Caused by poor hygiene
Contagious
A sexually transmitted infection
Smoking and obesity are strongly associated with HS and with worse severity, and both are worth addressing, but association is not causation.
Framing the disease as something the patient did wrong feeds shame, and shame is one of the documented reasons patients stop coming in.
Evidence
Studies of diagnostic delay consistently identify patient embarrassment and stigma alongside physician under-recognition as core drivers
The 2019 guidelines recommend counseling smoking cessation and weight management as adjuncts to treatment, not as substitutes for it
The lesions tend to be sterile, which is the clinical fact that unwinds the hygiene story
Practical tip
Lead with the disease model before you mention modifiable factors.
First: "This is an inflammatory condition of the hair follicle."
Second, and only after the patient has heard that it is not their fault: "Smoking makes it worse, and quitting is one of the most useful things you can do."
Mistake 4: Treating the skin and missing the rest
The short version: HS is systemic. Build comorbidity screening into every HS visit, because it rarely happens otherwise.
Mechanism
HS is a systemic inflammatory disease. The same patient carries elevated risk across three groups:
Metabolic and cardiovascular: metabolic syndrome, type 2 diabetes, cardiovascular disease, PCOS
Inflammatory: inflammatory bowel disease, spondyloarthritis
Mental health: depression, anxiety, suicidality
Primary care is the only setting that sees these patients longitudinally enough to catch all of it.
Evidence
Screening recommendations: the US and Canadian HS Foundations published evidence-based comorbidity screening recommendations (Garg et al., JAAD 2022). They cover depression, generalized anxiety disorder, suicide, smoking, substance use disorder, PCOS, obesity, dyslipidemia, diabetes, metabolic syndrome, hypertension, cardiovascular disease, IBD, spondyloarthritis, and sexual dysfunction, among others.
US practice: a National Ambulatory Medical Care Survey analysis of US HS visits found depression screening documented at only 2% of visits
UK practice: a GP survey found that while most GPs were confident diagnosing and treating HS, screening for cardiovascular risk and depression was uncommon
Practical tip
Build a one-line HS visit bundle into your template:
PHQ-9 and GAD-7
Smoking status
BMI and blood pressure
Lipid panel and HbA1c if not done in the past year
Menstrual and hirsutism history in women (PCOS)
Two screening questions for bowel symptoms and inflammatory back pain
Ask directly about pain, sleep, and intimacy; patients rarely volunteer these.
Mistake 5: Referring too late
The short version: tunnels and scars do not reverse. Refer at Hurley stage II, and send a packet that lets dermatology move fast.
Mechanism
Tunnels and scarring do not reverse with medication
Once a patient has reached Hurley stage II or III, the goal shifts from control to damage limitation, and surgery becomes part of the plan
Early systemic therapy is the window where you can still change the trajectory, and the biologic options have expanded meaningfully
Evidence
Three biologics carry FDA approval for moderate to severe HS in adults:
Biologic | FDA approval for HS |
|---|---|
Adalimumab | 2015 |
Secukinumab | 2023 (adults); March 2026 extension to adolescents 12 years and older weighing at least 30 kg, the first IL-17A option for that group |
Bimekizumab | November 2024 |
Where guidelines place them:
First-line for moderate to severe disease
Second-line for mild to moderate disease that fails initial therapy
Patients with a combined abscess and nodule count of 3 or more are generally candidates for biologic evaluation
Practical tip
Referral triggers for primary care:
Hurley stage II or III at any visit
Any draining tunnel or scar
Failure to respond after a full 12 week antibiotic course
Three or more active abscesses or nodules
An adolescent with progressive disease
Send the referral with what dermatology needs to move fast:
Hurley stage
Lesion count and sites
Date and duration of antibiotic trials
Smoking status and current weight
TB screening status, if you have it
That packet can shorten the path to biologic approval by a visit or more.
Practical reset
Diagnose
Recurrent nodules or abscesses in a skin fold, two or more episodes in 6 months: diagnose HS at the visit
Record Hurley stage at diagnosis and at every follow-up
Treat
Flares: intralesional triamcinolone over I&D unless fluctuant
Maintenance: doxycycline 100 mg twice daily for 12 weeks, topical clindamycin for mild disease
Counsel
Say "inflammatory follicle disease," never "hygiene"
Screen
PHQ-9, GAD-7, smoking, BMI, BP, lipids, HbA1c, PCOS, IBD, joint pain
Refer
Refer at Hurley II or III, tunnels, 12 week antibiotic failure, or 3 or more active lesions
Referral packet: stage, sites, lesion count, antibiotic history, smoking, weight
Recommended reading
Guidelines
Alikhan A, Sayed C, Alavi A, et al. North American clinical management guidelines for hidradenitis suppurativa, Part I and II: https://doi.org/10.1016/j.jaad.2019.02.067; https://pmc.ncbi.nlm.nih.gov/articles/PMC9131892/
Alhusayen R, Dienes S, Lam M, et al. North American clinical practice guidelines for the medical management of hidradenitis suppurativa in special patient populations. J Am Acad Dermatol. 2025;92(4):825-852. https://doi.org/10.1016/j.jaad.2024.11.071
Comorbidity screening
Garg A, Malviya N, Strunk A, et al. Comorbidity screening in hidradenitis suppurativa: Evidence-based recommendations from the US and Canadian Hidradenitis Suppurativa Foundations. J Am Acad Dermatol. 2022. https://pubmed.ncbi.nlm.nih.gov/33493574/
Overview
Hidradenitis suppurativa (Seminar). The Lancet, 2025. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)02475-9/fulltext
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👋🏻 Thank you for being here, DERM community!
Thank you for reading, and for taking this into your exam rooms.
The next patient who comes in with a "boil" that keeps coming back may leave your office with a diagnosis, years sooner than most.
Next issue: Hair, hives, and the thyroid you have not checked. We will walk through the hair and skin findings that should prompt a thyroid workup.
Have a restful weekend.
Until next time, stay curious and keep translating science into realistic hope.
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