How severe is my hidradenitis?
Count today's active lesions for an IHS4 severity score, and match your skin's overall picture to a Hurley stage — the same two measures dermatologists use to grade hidradenitis suppurativa. HS is famously underdiagnosed: if deep, painful boils keep returning in your armpits, groin, or under your breasts, that pattern has a name and real treatments. Everything stays on this device.
Recurrent painful lumps in the armpits, groin, buttocks, or under the breasts are not a hygiene problem and not bad luck with infections — they are the classic pattern of hidradenitis suppurativa, a chronic inflammatory skin condition that people typically live with for years before anyone names it. If that pattern sounds like yours, book a dermatologist visit whatever this page's numbers say. HS has real, effective treatments — and starting them earlier protects your skin from permanent tunnels and scarring.
Check everywhere HS shows up on you — both armpits, groin, buttocks, under the breasts — and count each lesion type across all of them. A mirror or a phone camera helps with awkward spots.
Count only currently active inflammatory lesions. Non-inflamed scarring, comedones and post-inflammatory changes are not counted.
Pick the stage that matches your worst-affected area. Hurley staging describes structural damage — tunnels and scarring — so it tends not to improve with medical therapy; the IHS4 count above is what tracks day-to-day activity. Not sure? Leave it blank — the lesion count works on its own.
Tap a selected stage again to unselect it.
Count your active lesions above, pick a Hurley stage, or both — the reading updates as you go.
This is an educational self-assessment, not a diagnosis — IHS4 and Hurley staging describe your skin at a point in time, and only a clinician examining you can confirm hidradenitis suppurativa or choose treatment. Bring the numbers to your GP or dermatologist rather than acting on them alone.
IHS4: Zouboulis CC, et al. Development and validation of the International Hidradenitis Suppurativa Severity Score System (IHS4). Br J Dermatol. 2017;177(5):1401–1409. · Hurley staging: Hurley HJ. In: Roenigk RK, Roenigk HH, eds. Dermatologic Surgery. New York: Marcel Dekker; 1989:729–739.
A single IHS4 number is a snapshot; a run of dated checks shows whether treatment is actually pulling activity down. Re-count during flares and after treatment changes, and pair this page with the Skin Flare Diary to capture what set a bad stretch off. When an appointment is coming up, the Derm Visit Prep tool can fold your saved scores into a printable visit sheet.
Saved only on this device — and browsers erase site data. A history clear, a private window, or Safari's automatic deletion after seven days without a visit will take this log with it. The fix is a free Dermington account: it backs this up automatically and puts it on every device you sign in to — details in how storage works.
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How the HS severity check works
The tool combines the two grading systems dermatology actually uses for hidradenitis suppurativa. The IHS4 — the International Hidradenitis Suppurativa Severity Score System, developed and validated by Zouboulis and colleagues (British Journal of Dermatology, 2017) — turns a lesion count into a severity score: each inflammatory nodule scores 1 point, each abscess 2, and each draining tunnel 4, summed across every involved site. A total of 3 or less is mild, 4–10 moderate, and 11 or more severe. Hurley staging (1989) is older and structural: stage I is abscesses without sinus tracts or scarring, stage II is recurrent abscesses with tunnels and scarring in widely separated areas, and stage III is diffuse involvement with interconnected tracts across a whole region. Activity moves; structure mostly doesn't — which is why you need both numbers.
One clinical measure from the source assessment is deliberately not here: HiSCR, the Hidradenitis Suppurativa Clinical Response (Kimball et al., British Journal of Dermatology, 2014). It's the endpoint HS drug trials use to declare a treatment response, and it only means something when measured against a formal clinician-scored baseline — so it belongs in your dermatologist's notes, not a self-check. What belongs here is the habit that makes that appointment count: HS is one of dermatology's most underdiagnosed conditions, with people cycling through years of "recurring boils" before the pattern gets its name. If that's you, a saved history of dates, counts, and stages from this page gives a dermatologist a running start.
Common questions
What is a hidradenitis suppurativa stage?
Hurley staging is dermatology’s shorthand for how much structural damage HS has done to a region of skin. Stage I means abscesses without sinus tracts or scarring, stage II means recurrent abscesses that have formed tunnels and scars in separated areas, and stage III means diffuse involvement with interconnected tracts across a whole region. The stage matters because it steers treatment — later stages usually need more than creams and short antibiotic courses.
Are the recurrent boils in my armpit actually HS?
Quite possibly, and this is exactly the pattern that goes unrecognized for years — deep, painful boils that keep coming back in the armpits, groin, buttocks, or under the breasts are the textbook presentation of hidradenitis suppurativa, not ordinary infections or hygiene problems. A one-off boil is usually nothing; the same spots flaring again and again is a pattern worth a dermatologist appointment, because HS is treatable and earlier treatment protects the skin from permanent tunnels and scarring.
How do I count lesions for the IHS4 score?
Count only what is currently active and inflamed, across every affected area of your body: tender inflamed nodules score 1 point each, abscesses 2 points each, and draining tunnels 4 points each. Old non-inflamed scars, blackhead-like comedones, and dark marks left by past flares are not counted. Totals of 3 or less read as mild activity, 4–10 as moderate, and 11 or more as severe.
Can my Hurley stage improve with treatment?
Generally no — Hurley stage describes structural damage like tunnels and scarring, which medical therapy rarely reverses, so the stage tends to hold or advance rather than retreat. That is precisely why the two measures on this page are separate: the IHS4 count tracks the day-to-day inflammation that treatment absolutely can bring down, while the stage tells you and your dermatologist what kind of treatment conversation to have. Established tunnels sometimes need a surgical fix even when medication controls the flares.
Where do my saved scores go?
Into your own browser’s local storage on this device — nothing is uploaded to Dermington or anywhere else. The trade-off is that clearing browser data erases the history, so back up from Your data if the trend matters to you. A saved run of dates, counts, and stages is also exactly the evidence a dermatologist wants at a first HS appointment, and the Derm Visit Prep tool can fold it into a printable sheet.