Itching is a common and often distressing symptom for many individuals undergoing dialysis. This persistent sensation can significantly affect daily life and overall well-being. This article explores the link between dialysis and itching, its underlying causes, various approaches for relief, and considerations for living with this condition.
Dialysis and the Itch Connection
Dialysis patients frequently experience itching, a condition medically known as uremic pruritus or chronic kidney disease-associated pruritus (CKD-aP). This type of itching is directly linked to kidney failure and does not typically present with a rash or other visible skin changes that would explain the sensation. The itching can vary in intensity, ranging from mild to severe, and may affect the entire body or specific areas such as the back, face, or the arm used for dialysis access. It can come and go or persist throughout the day, often worsening at night.
Up to 70% of individuals receiving hemodialysis report some degree of itching, with approximately half experiencing moderate to severe symptoms. Even patients with chronic kidney disease not yet on dialysis can experience CKD-aP, though it is more common and often more severe in those undergoing dialysis. This highlights the strong connection between impaired kidney function, dialysis, and this uncomfortable symptom.
Underlying Reasons for Itching
The specific mechanisms causing itching in dialysis patients are complex and not fully understood, but several factors are believed to play a role. A primary contributor is the accumulation of uremic toxins in the body due to the kidneys’ inability to filter waste effectively. These harmful substances can build up and potentially trigger the itching sensation.
Another significant factor is systemic inflammation. Chronic kidney disease often leads to a state of ongoing inflammation in the body, which may contribute to itching. Elevated levels of inflammatory markers, such as C-reactive protein and certain cytokines like interleukin-6, have been observed in dialysis patients experiencing pruritus. Imbalances in minerals, particularly high levels of phosphorus, calcium, and parathyroid hormone, are also implicated. These mineral disturbances can lead to deposits in the skin, potentially irritating nerve endings and causing itch.
Dry skin, known as xerosis, is very common in individuals with end-stage kidney disease and can exacerbate itching. Changes in sweat and oil glands due to kidney failure contribute to this dryness. Additionally, some research suggests that nerve abnormalities, including an imbalance in the endogenous opioid system, might contribute to the itch by altering how nerve signals are transmitted. Specifically, an overactive mu-opioid receptor system and an underactive kappa-opioid receptor system are thought to promote itching.
Approaches to Relieve Itching
Managing itching in dialysis patients involves a multi-faceted approach, combining medical treatments with lifestyle adjustments. Optimizing dialysis is a primary strategy; healthcare providers may increase session frequency or duration to improve the removal of uremic toxins. Addressing high phosphorus levels through dietary restrictions and phosphate binders also helps, as dialysis does not efficiently remove phosphorus.
Several medications alleviate the itch. Gabapentin and pregabalin, typically used for nerve pain, reduce itching by affecting nerve signals. These are often started at low doses and adjusted as needed, typically taken after dialysis sessions. Kappa-opioid agonists like difelikefalin and nalfurafine rebalance the opioid receptor system to reduce itch signals. Difelikefalin is approved for moderate to severe itching in hemodialysis patients and administered intravenously after each treatment. Nalfurafine has also been shown to effectively reduce itching in hemodialysis patients.
Beyond systemic medications, topical agents and general skin care practices are important. Emollients and moisturizers, especially those free of alcohol and fragrances, can help combat dry skin when applied regularly, particularly after bathing. Lukewarm baths with oatmeal or baking soda, avoiding harsh soaps, and wearing cotton clothing can also provide relief. In some cases, phototherapy with ultraviolet B (UVB) light has been used to reduce itching, though it may take time to show effects and requires careful consideration of potential risks.
Living with Itching and When to Seek Help
Chronic itching significantly impacts a dialysis patient’s quality of life. It often leads to sleep disturbances, causing fatigue and affecting mood. Scratching can result in skin damage, such as excoriations or thickened skin, and may increase the risk of infection. Itching can also affect social interactions and daily activities, contributing to feelings of distress or depression.
To cope with the persistent itch, individuals can employ several strategies in their daily lives. Maintaining a comfortable environment by avoiding extreme temperatures and using humidifiers in dry climates may help. Distraction techniques, such as engaging in hobbies or light activities, can momentarily shift focus away from the sensation. Keeping nails trimmed can minimize skin damage from scratching.
Dialysis patients should communicate openly with their healthcare team about itching. Many do not report symptoms, possibly assuming it is a normal part of dialysis. Prompt recognition and treatment are important for managing the condition and preventing further complications. Patients should consult their doctor if itching is severe, disrupts sleep, affects daily activities, or if new symptoms develop. The healthcare team can assess the underlying causes and adjust treatment plans to provide the best possible relief.