Itching (pruritus) is a common complaint among patients with chronic kidney disease especially in patients who are on dialysis. Surveys done in patients on dialysis about pruritus reported a prevalence between 20% to 60%. More importantly, patients who are suffering from itching do not complain about it to the medical staff. There is also a lack of awareness among the medical staff about itching and its management.

What causes itching in dialysis patients?

No single cause has been identified for itching in patients with chronic kidney disease. Many risk factors are associated with itching in patients on dialysis. They are

1. Inadequate dialysis
2. Dry skin
3. Increased parathyroid hormone (PTH) levels
4. Increased calcium and phosphorus levels in blood
5. Increased magnesium and aluminum levels in blood

When and where in the body itching occurs?

The symptoms may be different in each patient.

• It commonly affects back, but it may also affect legs, hands, head(scalp), trunk also. Sometimes discontinuous areas may be affected (example: face and leg).
• Symptoms may be worse at night
• Can lead to sleep deprivation
• It is symmetrical (affecting both sides of body, example: right and left calves)
• Itching is more after exposure to heat and stress
• Skin generally looks normal and some patients have excessive scratching marks

Other causes of itching (like skin diseases, infections etc.,) needs to be considered if

• Symptoms do not respond to treatment or
• If there are any skin changes like rash etc., or
• If itching is asymmetrical (like localized to a single area or one side of the body)

Management

Management of itching in dialysis patients needs optimizing the dialysis and correcting the laboratory abnormalities and treatment specific to itching.

Topical therapy

• Application of coconut oil can relieve itching in some patients
• Avoiding dryness of skin can help reducing the symptoms
• Topical creams containing paraffin and high-water content application tend to relieve the symptoms of itching

Correcting laboratory abnormalities

• Correction of calcium, phosphorus and parathyroid hormone levels if they are abnormal with medications can improve itching.

Adequate dialysis

• Patients who are not on adequate dose of dialysis for them show improvement in itching on reaching their prescribed dialysis dose.
• Some patients may respond by increasing further dose of dialysis.

Medications

• If patients do not respond to above measures then medications are prescribed by treating nephrologist based on individual patient assessment.
• Variety of medications and creams are used like
  • Gabapentin, pregabalin
  • Capsaicin cream
• These medications are to be used only under supervision of treating nephrologist because of the side effects associated with them

Refractory cases

• Few patients do not respond to any of the above measures. In such patients Ultraviolet B (UVB) phototherapy is tried.
• Kidney transplantation is a definitive treatment of itching. There will be complete resolution of itching after kidney transplantation

Dr Kishore Kumar Ariga

Nephrologist and renal transplant physician