If you have prurigo nodularis, you probably know the hardest part is not the nodules. It is the itch that never fully switches off. For decades there was another hard part: no medicine was approved for PN at all. Doctors borrowed treatments from other skin diseases and hoped they would help. That changed only in 2022. Since then the field has moved faster than almost any other corner of dermatology, and this article lays out the full picture, from the two approved medicines to the pills now in testing.
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What's approved today
Exactly two medicines currently have FDA approval specifically for prurigo nodularis. Both are biologics, meaning they're injectable medications made from proteins that block specific immune signals in the body.
Dupixent (dupilumab). Approved in September 2022, this was the first-ever drug approved for PN in the US. It works by calming down two of the immune signals behind "type 2 inflammation," the overactive immune response that drives the itch in PN. This approval was based on two large studies called PRIME and PRIME2, run by Sanofi and Regeneron.
Nemluvio (nemolizumab). Approved in August 2024 by Galderma. It blocks a receptor for IL-31, a signaling molecule that researchers sometimes call "the itch signal," because it's what actually carries the itch message between immune cells and nerves. This approval came from two studies called OLYMPIA 1 and OLYMPIA 2. But here's the thing: a controlled study can't tell you how a medicine performs in everyday, real life outside of a research setting. So Galderma is now running a real-world study following 600 people with moderate to severe PN who are already taking nemolizumab, to fill in that gap.
So here's the difference: a patient diagnosed in 2021 had zero approved treatment options. A patient diagnosed today has two. That's genuinely good news. The honest downside is that both options are injections, and they don't work for everyone. Which is exactly why the current wave of ongoing trials matters so much.
Worth being upfront about: there's still no cure. The British Association of Dermatologists sums it up in a single word in their patient guide, "no." The reason is that current treatment focuses on controlling the itch and the nodules, not eliminating the underlying cause, which nobody fully understands yet. PN can sometimes improve on its own over time, but for some people that takes months or even years, which is a really long time to wait when the itch is keeping you up at night.
What researchers are studying now
The next generation of PN treatments is mostly pills, not injections. That's actually a big deal for practical reasons, not just scientific ones: a pill doesn't need refrigeration, a clinic visit, or learning how to give yourself a shot. Two programs stand out right now.
Povorcitinib (Incyte). This is an oral JAK1 inhibitor, meaning a pill that blocks one of the enzymes immune cells use to pass along inflammation signals. In an earlier study presented in 2024, people taking povorcitinib had significant improvements in both itch and skin lesions compared to those on a placebo. Incyte has since moved it into a larger, later-stage trial called STOP-PN1 (NCT06516952). This one isn't listed on our platform, so check its current status directly on ClinicalTrials.gov if you want to follow it.
Soficitinib, also called ICP-332 (InnoCare). This is an oral TYK2 inhibitor, a related but distinct way of blocking inflammation signals. The first patient in a global study of 135 people with PN has already received their first dose, and the study is currently recruiting. The same drug already succeeded in a later-stage study for atopic dermatitis, which is part of why researchers are optimistic about testing it for PN too.
Beyond these two, as of August 2026, other studies currently recruiting include additional biologic drug candidates from Chinese companies: MG-K10 from Shanghai Mabgeek Biotech (in a later stage of testing) and SHR-1819 from Guangdong Hengrui Pharmaceutical. Academic hospitals are involved too, including Peking University First Hospital, UMC Utrecht, and University Hospital Schleswig-Holstein, each running their own PN research. So the range of who's involved is pretty wide: two companies that already have approved drugs, two newer biologic developers, and university hospitals asking questions that industry doesn't typically fund.
One gap researchers are only now starting to close is kids. Both approved medicines were tested in adults first, and Sanofi is now running a small study in 18 participants ages 6 months to 18 years old to figure out how dupilumab works in younger bodies. In total, there are only 8 PN studies recruiting worldwide right now. That's not a lot. Several of them only run in China or Europe, which means each individual US study carries real weight for American patients.
Why PN research takes time
PN went from having zero approved drugs to a genuinely competitive pipeline in about four years. But it took decades just to get to that starting point. A few specific reasons explain why.
The measurement problem. Itch is invisible. You can't see it on a scan or find it in a blood test. So PN studies had to build their results around how patients rate their own symptoms, using something called the Worst Itch Numeric Rating Scale, where you score your worst itch on a scale from 0 to 10. Most studies count a drop of 4 points or more as a real improvement, usually paired with a doctor's visual assessment of the skin. That combination is unusual. In a lot of diseases, the main result comes from a machine reading test results, and the patient is really just a source of samples. In PN, the patient is the measuring instrument, and the entire result depends on their own rating. Getting regulators comfortable with that approach took years, and the major drug trials for Dupixent and Nemluvio helped establish that standard.
The recognition problem. PN often goes unrecognized. A 2025 review found that unclear definitions of the disease still lead to delayed diagnosis and treatment. Someone who's never diagnosed can't join a study, and a disease that doctors often miss struggles to attract research funding. This also means we don't really know how many people actually have PN, published US estimates range widely, anywhere from about 7 to 72 cases per 100,000 people. One 2019 analysis of insurance claims landed at about 34 per 100,000, which works out to roughly 170,000 Americans. That wide a range is itself a sign of just how inconsistent diagnosis has been.
The representation problem. PN doesn't affect everyone equally. A Johns Hopkins study of 909 patients found that Black patients were more than 3 times as likely to have PN as white patients. Yet dermatology research has historically skewed toward white participants. Companies now say diverse recruitment is a priority for PN research, and it's part of the reason platforms like this one exist: the people carrying the heaviest burden of a disease should be represented in the research that shapes its treatments.
The supply problem. With only 8 studies recruiting worldwide, someone who wants to contribute to PN research doesn't have many options to choose from. It also means there's a small pool of people available to help answer the field's open questions. Compare that to atopic dermatitis, where hundreds of studies are running at the same time, and the difference in how fast each field moves starts to make a lot more sense.
Does PN affect more than the skin?
It seems to. A UK study that followed 2,416 people with PN found higher rates of several conditions compared to matched people without PN: atopic dermatitis was about two and a half times more common, and type 2 diabetes, depression, coronary heart disease, anxiety, and chronic kidney disease were all meaningfully elevated too. The same study found overall death rates were about a third higher in the PN group, something researchers think is due to this pile-up of other health conditions rather than PN itself. A separate 2024 global study also found higher cardiovascular risk in people with PN.
The autoimmune connection became clearer in 2025. A large study compared about 18,000 adults with PN against the same number of closely matched people without it, then tracked which autoimmune conditions each group ended up being diagnosed with afterward. Lupus showed up roughly twice as often in the PN group. Psoriasis showed up more than three times as often, and Sjögren syndrome nearly twice as often. Several other autoimmune conditions researchers checked, including rheumatoid arthritis and inflammatory bowel disease, showed no meaningful difference at all, which is actually reassuring in its own right.
Two important things to keep in mind here. First, this is a pattern seen across a very large group of people, not proof of a direct cause, and it doesn't mean PN itself is an autoimmune disease. Second, this is part of why a doctor might ask about symptoms that seem completely unrelated to your skin.
None of this means PN determines your future health. It just means this disease deserves whole-person care, so bring these questions to your doctor, not just to a skin appointment.
Common myths
"It's contagious."
Not true. PN comes from immune and nerve signals happening inside the skin itself. You can't catch it from someone, and you can't give it to anyone either.
"It's just a scratching habit."
The scratching is a symptom, not the actual cause. PN is what's called a "neuroimmune" disease, meaning it involves both the immune system and the nerves. Inflammation and overly sensitive skin nerves create an itch that's incredibly hard to resist, and then scratching builds even more nodules on top of that. Telling someone with PN to "just stop scratching" completely misunderstands what's actually happening in their body.
"It runs in the family, so nothing can change it."
PN itself isn't directly inherited. What can run in families is something called atopy, the allergic tendency behind conditions like eczema and asthma, and atopy is linked to PN. So having a family history might raise your background risk somewhat, but PN isn't passed down the way a truly inherited condition would be.
"Nothing can be done."
This was almost true before 2022. It's not true anymore. There are now two FDA-approved medicines, and oral (pill) options are currently being tested in later-stage trials.
What prurigo nodularis looks like, and where it shows up
The nodules are firm, raised bumps with a thick, rough surface, ranging anywhere from a few millimeters to a few centimeters wide. On darker skin, they often show extra pigmentation. Because they get scratched so much, many end up crusted over or broken open.
Does prurigo nodularis affect the scalp?
Yes, it can, most commonly at the back of the head. But the scalp usually isn't where PN starts. The typical pattern is symmetrical: nodules appear on the outer surfaces of both arms and both legs, often along with the upper back, belly, and lower back. The palms, soles, face, and skin folds are usually spared.
There's one detail dermatologists find really useful, and patients often notice it themselves: skin you can't physically reach tends to stay clear. The middle of your upper back is the classic example, and that clear patch actually has a name, the "butterfly sign." It's a strong clue that scratching is what's actually building the nodules, since the disease stops wherever your hands can't reach.
How severity is graded, and what care usually looks like at each level
PN doesn't have a formal staging system, no "stage 1 to 4" like some diseases. Instead, doctors grade it as mild, moderate, or severe, based mostly on how many nodules you have and how intense the itch is. Clinical trials also use something called the IGA scale, where a doctor rates the skin from "clear" to "severe." This is just a description of typical practice, not advice about your specific case.
Mild. A limited number of nodules, and itch that's annoying but not taking over your day. Care at this stage usually stays focused on general skin treatments a dermatologist prescribes, plus treatment applied directly to the nodules themselves.
Moderate. More nodules, and itch that starts interfering with sleep and daily life. This is typically where the conversation about broader, body-wide treatment begins, and it's often where people become eligible for clinical trials, since most PN studies require moderate to severe disease along with a high itch score to qualify.
Severe. Nodules are widespread, and the itch score sits at the very top of the 0-to-10 scale. Both currently approved biologics were tested specifically in this group, and it's the population most ongoing trials are designed around.
If you're not sure where you fall, ask your dermatologist how they'd grade your PN. That single grade often determines which clinical trials you'd even qualify for.
How to find a PN study
AllClinicalTrials.com lists prurigo nodularis trials that are recruiting in the US, including pediatric and observational options. One example: Sanofi's study testing dupilumab in children and teens, ages 6 months to 18 years old.
The application takes about 5 minutes: you answer a few questions about your diagnosis and history, and if a study near you looks like a match, the research team contacts you. There's no obligation at any point, and joining a screening call doesn't commit you to anything.
If you're earlier in your journey and still figuring out the disease itself, start with our guide What Is Prurigo Nodularis?
Common questions
What is prurigo nodularis, in simple terms? Prurigo nodularis is a long-lasting skin condition where firm, rough-surfaced nodules form and itch relentlessly. The itch actually comes first, driven by immune and nerve signals in the skin, and the nodules build up as a result of the scratching that itch triggers. It most often starts in people in their 50s and 60s, and it's not something you can catch from anyone else.
What is WI-NRS? It stands for the Worst Itch Numeric Rating Scale. You rate your worst itch on a scale from 0 to 10. Most PN trials count an improvement of 4 points or more as a meaningful response to treatment.
What causes prurigo nodularis? Nobody has the full answer yet. What researchers do know is that both immune signals and nerve signals in the skin go wrong at the same time, which is why doctors call PN a "neuroimmune" disease. That combination creates an itch that's incredibly hard to resist, and scratching is what actually builds the nodules. PN itself isn't inherited, though the allergic tendency that often comes along with it does tend to run in families.
Where on the body does prurigo nodularis appear? Usually on the outer sides of the arms and legs, in a fairly even, symmetrical pattern on both sides. The upper back, belly, and lower back can be affected too, and yes, PN can reach the scalp, most often at the back of the head. The palms, soles, face, and skin folds are usually spared. So is any skin you physically can't reach, the middle of your upper back often stays clear, something doctors call the "butterfly sign" and use as a helpful clue when confirming a PN diagnosis. Individual nodules range from a few millimeters to a few centimeters in size.
Can prurigo nodularis kill you? PN itself isn't a fatal disease. A UK study that followed 2,416 people with PN found overall death rates were about a third higher than in a matched comparison group, something researchers link to the other health conditions that tend to come along with PN, not to the skin disease itself. That's a finding based on large groups of people, not a personal prediction for any one individual, so it's worth talking through your own health picture with your doctor.
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