Itching is one of the most common and distressing symptoms experienced by people on dialysis, but dialysis itself is not the direct cause. The condition, known as chronic kidney disease-associated pruritus (CKD-aP), stems from the underlying kidney failure and its wide-ranging effects on the body’s chemistry, immune system, and nerves. Roughly half of hemodialysis patients report being at least moderately bothered by itching at some point, and the itch tends to persist: among those who report it initially, about six in ten still have it months later. The good news is that the mechanisms are increasingly well understood, and treatments have improved considerably in recent years.
How Common Is the Problem
The scale of dialysis-related itching is often underappreciated by people who do not live with it. A large international study tracking nearly 8,000 hemodialysis patients found that about 36% were at least moderately bothered by itchy skin at any given assessment, and roughly 51% experienced moderate-to-severe itching at one or both of two time points spaced four months apart.1American Journal of Kidney Diseases. Longitudinal Changes in Pruritus and Association With Clinical and Patient-Reported Outcomes Among Patients Receiving Maintenance Hemodialysis: The Dialysis Outcomes and Practice Patterns Study Among patients whose itching was moderate or worse at the first check, 61% remained that way at the second check. Only about 28% improved over the interval. These numbers paint a picture of a symptom that is not a passing nuisance for most people. It lingers, and it tends to be undertreated because many patients assume itching is just something they have to live with.
What Actually Causes the Itch
CKD-aP is not caused by one single thing. Researchers have identified several overlapping mechanisms, and most patients probably experience itching driven by a combination of them.2PubMed Central. Uremic Pruritus: From Diagnosis to Treatment The main contributors include immune system overactivation, an imbalance in the body’s natural opioid signaling, buildup of uremic toxins, disrupted mineral metabolism, and changes to the skin itself.
Immune Dysregulation and Inflammation
Kidney failure puts the immune system into a state of chronic low-grade inflammation. One molecule that has attracted particular attention is interleukin-31 (IL-31), a signaling protein involved in itch sensation. Hemodialysis patients with itching have dramatically higher blood levels of IL-31 compared with dialysis patients who do not itch, and both groups have far higher levels than healthy people.3PubMed Central. The Serum Level of IL-31 in Patients with Chronic Kidney Disease-Associated Pruritus: What Can We Expect? The relationship between IL-31 levels and itch severity trended toward significance in that study but did not quite cross the threshold, which suggests IL-31 is an important part of the picture without being the whole story.
Opioid Receptor Imbalance
Your body has two types of opioid receptors in the skin that help regulate itch: mu-opioid receptors, which tend to promote itching, and kappa-opioid receptors, which tend to suppress it. In dialysis patients with itching, the expression of kappa receptors in the skin is significantly lower than in dialysis patients without itching, and the worse the itch, the fewer kappa receptors are present.4PubMed. Opioid receptors expression in the skin of haemodialysis patients suffering from uraemic pruritus Mu receptor levels, by contrast, were similar between itchy and non-itchy patients. This imbalance helps explain why a new class of drugs targeting kappa receptors has been so effective, as discussed later.
Mineral and Toxin Buildup
For years, elevated blood phosphorus was assumed to be a major driver of dialysis itch. There is some support for this: one study found that hemodialysis patients with itching had significantly higher levels of calcium, phosphorus, and alkaline phosphatase compared with non-itchy patients.5PubMed Central. The Comparison of Renal Osteodystrophy Indices in Hemodialysis Patients with and without Pruritus But the story is not straightforward. A post hoc analysis of two large clinical trials found no significant correlation between serum phosphate levels and itch severity, either at baseline or after 12 weeks.6PubMed Central. Pruritus Severity and Serum Phosphate in CKD: A Post Hoc Analysis of Difelikefalin Studies This means that while keeping phosphorus under control is important for many reasons, simply lowering it will not reliably stop the itching.
Dry Skin and Sweat Gland Dysfunction
Dry skin (xerosis) is extremely common in dialysis patients, partly because kidney failure reduces the ability of sweat glands to function normally, leading to decreased moisture on the skin’s surface.7PubMed. Dry skin (xerosis) in patients undergoing maintenance haemodialysis: the role of decreased sweating of the eccrine sweat gland Interestingly, though, studies have not found a direct correlation between how dry someone’s skin is and how severely they itch. Xerosis probably lowers the threshold for itching by damaging the skin barrier, but it is not the root cause on its own.
Does the Type of Dialysis Matter
People sometimes wonder whether switching from hemodialysis to peritoneal dialysis (or vice versa) would ease their itching. The evidence here is genuinely mixed and a bit frustrating. One study of 380 patients found that itching severity was lower in peritoneal dialysis patients, and that peritoneal dialysis independently predicted milder itch scores.8PubMed Central. A Comparison of Uremic Pruritus in Patients Receiving Peritoneal Dialysis and Hemodialysis But another study of more than 600 patients found the opposite: peritoneal dialysis patients were actually more likely to have itching and reported higher itch intensity.9Kidney Research and Clinical Practice. Comparison of uremic pruritus between patients undergoing hemodialysis and peritoneal dialysis A third study found the rates and severity were similar between the two modalities.10PubMed Central. Substance P and intensity of pruritus in hemodialysis and peritoneal dialysis patients
The takeaway is that switching dialysis type for the sole purpose of reducing itching is not reliably supported by the data. The itch arises from kidney failure itself, and both forms of dialysis leave enough uremic toxins and metabolic disruption behind to trigger it.
Optimizing Dialysis to Reduce Itching
Even though dialysis type does not seem to make a consistent difference, the quality and technique of hemodialysis can matter. A large prospective study found that lower dialysis adequacy scores and the use of low-flux dialyzer membranes were independent predictors of worse itching.11PubMed Central. Uremic Pruritus in Hemodialysis: Mechanisms, Burden, and Emerging Therapies High-flux filters, which remove a broader range of middle-weight molecules, have been associated with improved itch in multiple studies. One randomized trial comparing medium cut-off (MCO) dialyzers with standard high-flux dialyzers found that the MCO group had less widespread itching and fewer sleep disturbances caused by scratching after 12 weeks.12Scientific Reports. Randomized controlled trial of medium cut-off versus high-flux dialyzers on quality of life outcomes in maintenance hemodialysis patients
A specialized dialyzer membrane made of polymethylmethacrylate (PMMA) has also shown promise. In a crossover study, patients who switched to PMMA membranes for three months experienced a significant drop in their itch scores, while patients on standard membranes during the same period did not improve at all.13PubMed. Polymethylmethacrylate efficacy in reduction of renal itching in hemodialysis patients: crossover study and role of tumor necrosis factor-alpha PMMA membranes are thought to work by adsorbing certain inflammatory molecules that standard filters miss. If your itching is severe and persistent, asking your nephrologist about the type of dialyzer being used is worth the conversation.
Medications That Target the Itch Directly
Difelikefalin, the Kappa-Opioid Approach
The opioid imbalance described earlier opened the door for a targeted treatment: difelikefalin, an intravenous drug that activates kappa-opioid receptors. A systematic review of clinical trials found that it significantly reduced itch intensity as measured by standard itch rating scales, and also improved quality-of-life scores.14PubMed Central. Difelikefalin in the Treatment of Chronic Kidney Disease-Associated Pruritus: A Systematic Review In a Japanese placebo-controlled trial, patients receiving difelikefalin saw about twice the reduction in itch scores compared with those receiving placebo over four weeks.15PubMed. Difelikefalin for Hemodialysis Patients with Pruritus in Japan Difelikefalin is given through the dialysis line at the end of each session, so it adds minimal inconvenience to the treatment routine. It was the first drug approved specifically for CKD-aP in hemodialysis patients and represents a real shift in how this problem is managed.
Gabapentin and Pregabalin
Before difelikefalin, gabapentin was the most commonly used prescription medication for dialysis itch. It works on nerve signaling rather than the opioid system. A systematic review of studies using gabapentin for uremic pruritus found improvements ranging from a 5.7 to 9.4 point drop on a 10-point scale, which is substantial.16PubMed Central. Gabapentin for uremic pruritus in hemodialysis patients: a qualitative systematic review The catch is side effects. Drowsiness, dizziness, and fatigue are common, and about one in six patients in one real-world study had to stop the drug because they could not tolerate it.17Journal of Pain and Symptom Management. Efficacy and Safety of Gabapentin for Uremic Pruritus and Restless Legs Syndrome in Conservatively Managed Patients With Chronic Kidney Disease For patients who cannot tolerate gabapentin, pregabalin is a reasonable alternative. In one clinical series, pregabalin relieved itching in about 80% of patients who had failed gabapentin, and the combined success rate of trying gabapentin first and then pregabalin if needed was around 85%.18PubMed. Uraemic pruritus: relief of itching by gabapentin and pregabalin Doses used in kidney disease are much lower than the typical neurological doses because the kidneys cannot clear the drug efficiently.
Skincare and Topical Treatments
Given that dry, fragile skin lowers the threshold for itching, consistent moisturizing is considered a baseline intervention. Various topical formulations have been studied, including urea-based creams, ceramide-containing emollients, natural oils, capsaicin cream, and glycerin-based moisturizers, all of which have shown some benefit in reducing itch symptoms.19PubMed Central. Topical regimens for the management of uremic pruritus No single product has emerged as clearly superior, so the best topical is whichever one you will actually use every day. Regular application after dialysis sessions and before bed tends to be the most practical routine.
Capsaicin cream deserves a special mention because it works differently from moisturizers. It depletes substance P, a neuropeptide involved in transmitting itch signals, from nerve endings in the skin. The burning sensation it produces initially can be off-putting, but it typically fades over a week or two of regular use. It tends to work best for localized itching rather than the whole-body itch that many dialysis patients experience.
Phototherapy for Stubborn Cases
When topical treatments and medications fall short, narrowband ultraviolet B (NB-UVB) phototherapy is another option. This involves exposing the skin to a specific wavelength of UV light, typically twice a week, under controlled clinical conditions. In one study of 38 patients, itch intensity began to drop by about the sixth session, and nearly all patients achieved complete improvement by the end of treatment, which averaged 13 sessions.20PubMed Central. Effectiveness of Narrowband Ultraviolet Light in Chronic Kidney Disease-Associated Pruritus However, a randomized controlled trial gave a more cautious picture: both the UVB group and the control group improved during treatment, though the UVB group showed a significant reduction in the body surface area affected by itching and had lower itch scores at certain time points.21PubMed. Narrowband ultraviolet B phototherapy for patients with refractory uraemic pruritus: a randomized controlled trial The effect appears real but modest in controlled settings, and the practical barriers (frequent clinic visits, skin cancer screening) mean phototherapy is typically reserved for cases that have not responded to other approaches.
One reason UVB light may help relates to vitamin D. Kidney disease impairs the body’s ability to produce active vitamin D, and vitamin D plays a role in skin barrier function and calcium regulation in the upper layers of the skin. Disruption of the skin’s calcium gradient has been linked to CKD-aP, and there is a plausible mechanism by which UV-stimulated vitamin D could help restore normal keratinocyte function, though this connection has not been firmly established.22Kidney Research and Clinical Practice. Vitamin D and narrowband ultraviolet B phototherapy for chronic kidney disease-associated pruritus
Acupuncture and Acupressure
For patients looking beyond conventional medicine, acupuncture has accumulated a reasonable evidence base. A systematic review and meta-analysis found that acupuncture was more effective than conventional treatment for uremic pruritus, and that combining acupuncture with hemodialysis was significantly more effective than hemodialysis alone.23Journal of Pain and Symptom Management. Acupuncture for Uremic Pruritus: A Systematic Review and Meta-Analysis However, when acupuncture was compared head-to-head with medications, the difference was not statistically significant, suggesting it works about as well as drug therapy rather than better. Acupressure, a needle-free variant that applies pressure to traditional acupuncture points, has also shown benefit in smaller studies.24Jurnal Keperawatan Komprehensif (Comprehensive Nursing Journal). Is Acupressure Effective To Treat Pruritus In Hemodialysis Patients? A Literatur Review The appeal of these approaches is their low side-effect profile. They are reasonable add-ons, even if the evidence quality is not as strong as for pharmaceutical treatments.
Why Itching Matters More Than People Think
There is a tendency, even among some clinicians, to treat dialysis-related itching as a minor annoyance. The data say otherwise. Patients with extreme itching face more than a five-fold increased risk of depressive symptoms and about a three-fold increased risk of sleep disturbance compared with patients who are not bothered by itch.25Kidney Medicine. Association of Chronic Kidney Disease–Associated Pruritus With the Sleep Disturbance, Depression, Pain, Anxiety, and Low Energy/Fatigue Symptom Cluster: A Retrospective Cohort Study Anxiety risk increases at a similar rate. These symptoms cluster together and compound one another: poor sleep worsens depression, depression lowers the threshold for pain and itch, and the cycle feeds itself.
Beyond mental health, CKD-aP is associated with higher hospitalization rates and increased mortality. Studies consistently show that patients with severe itching have worse overall outcomes compared with those whose itch is mild or absent.26Clinical Kidney Journal. Epidemiology and burden of chronic kidney disease-associated pruritus Whether the itching itself contributes to worse outcomes or whether it is a marker of more poorly controlled kidney disease is debated, but the association is strong enough that treating itch aggressively is increasingly seen as a quality-of-care issue, not a comfort issue.
Tracking Your Itch and Talking to Your Team
One of the biggest barriers to getting help is that many patients never mention their itching, and many dialysis clinics do not routinely ask about it. If you are living with itch, bringing it up explicitly with your nephrologist or dialysis nurse is the essential first step. Having some way to describe the severity helps. The most widely used clinical tool is a simple 0-to-10 numerical rating scale asking about your worst itch over the past 24 hours. Research has established that a drop of 3 or more points on that scale represents a clinically meaningful improvement, which gives you and your doctor a concrete goal to aim for.27PubMed Central. Psychometric validation and meaningful change thresholds of the Worst Itching Intensity Numerical Rating Scale for assessing itch in patients with chronic kidney disease-associated pruritus
Keep in mind that not all itching in a dialysis patient is CKD-aP. Other causes, including allergic reactions to medications, contact dermatitis from dialysis tubing or tape, fungal skin infections, and scabies, should be ruled out. If your itching started suddenly, is concentrated in one spot, or is accompanied by a visible rash, a dermatologic evaluation makes sense before assuming it is uremic in origin. The distinction matters because the treatment is completely different.
Putting Together a Treatment Plan
Because CKD-aP involves multiple mechanisms, treatment tends to work best when it is layered rather than relying on a single intervention. A reasonable approach usually looks something like this:
- Baseline skincare: Daily emollient use, avoiding harsh soaps and very hot water, and keeping the skin hydrated especially after dialysis sessions.
- Dialysis optimization: Ensuring adequate dialysis delivery (high Kt/V), using high-flux or MCO dialyzer membranes, and managing phosphorus and calcium through diet and binders.
- Targeted medication: Difelikefalin for patients on hemodialysis, or gabapentin/pregabalin started at low doses with careful monitoring for drowsiness.
- Add-on therapies: Capsaicin for localized itch, phototherapy for refractory cases, acupuncture or acupressure for patients interested in nonpharmacological options.
The order matters. Jumping straight to medication without addressing skincare and dialysis adequacy leaves easy wins on the table. Conversely, insisting that “better moisturizing” alone will fix severe, whole-body itch driven by opioid imbalance and immune activation is equally unhelpful. The best outcomes come from matching the aggressiveness of treatment to the severity of the symptom, and from recognizing that what works for one person may not work for the next.