Itch Diminishes Hemodialysis Patients’ Quality of Life

Uremic pruritis, or itch, can significantly diminish quality of life and interfere with sleep, work, and social interactions for a large proportion of hemodialysis patients, according to findings from two poster presentations at the ASN annual meeting.

Pruritus “is a horrible thing . . . . It’s one of the most debilitating facets of the disorder,” said Adrienne Ste. Marie, director of project management at Acologix in Hayward, Calif. Moderate to extreme pruritus affects about 40 percent of hemodialysis patients in the United States. Besides diminishing quality of life, it can also shorten lives. The Dialysis Outcome and Practice Patterns Study reported that associated sleep disturbances increased mortality (P <0.0001), so the condition is not just a matter of “itch.”

According to lead authors Michael Germain, MD, of Western New England Renal and Transplant Associates in Springfield, Mass., and James Tumlin, MD, of the Chattanooga Kidney Center and the University of Tennessee in Chattanooga, this investigation, the ITCH National Registry, is the first longitudinal observational study of uremic pruritus.

Using multiple instruments of health-related quality of life, the researchers reported on temporal and spatial patterns of itching and on quality of life issues related to pruritus.

The 103 patients in the multicenter study were ≥18 years old (mean = 56), on hemodialysis three or more times per week, and had an itch severity >10 mm on a visual analog scale (VAS; 0 = no itching, 100 mm = worst possible). They had had end stage renal disease for a mean of 4.1 years. The study population was two-thirds African-American, reflecting the demographics of the study sites in the southeastern United States.

Participants completed SKINDEX-10 and Brief Itch Inventory (BII) surveys. SKINDEX-10 includes questions about occurrence of itching, a mood domain (annoyance, depression, or embarrassment about itching), and a social domain (influence of itching on interactions with people, desire to be with people, and effect on work or enjoyable activities). BII asks about mood and interference with work, sleep, enjoyment of life, and relations with other people. Patients also completed the Beck Depression Index and the Medical Outcomes Survey Sleep Questionnaire.

Despite relatively well-controlled calcium, phosphate, PTH, and Kt/V (mean = 1.69), patients had a high degree of itching, with a median worst nighttime score on the VAS of 60 mm. Both SKINDEX-10 and BII scores reflected lower health-related quality of life, including changes in mood, sleep, and social function with each 10 mm VAS increase of itch intensity. The researchers concluded that even small reductions in itch intensity could improve patients’ quality of life.

The same patients also completed surveys of itch patterns using body diagrams. The majority (59 percent) of patients had had pruritus on a daily or nearly daily basis for more than one year, and 41 percent had it this frequently for more than five years. The spatial pattern of pruritus was unique to each patient. Over 12 weeks of follow-up, itch intensity fluctuated for many patients, appeared to be cyclical for some, and rarely disappeared if the initial VAS intensity score was >40 mm.

The investigators concluded that uremic pruritis tends to be unremitting in frequency but may fluctuate in intensity over weeks to months. They also said the spatial pattern suggests a neurogenic process and is not consistent with calcium-phosphate deposition in the skin or other local causes. Ste. Marie added that itch did not correlate with dialysis days.

The poster sessions were titled “Correlation between Uremic Pruritis Intensity and Quality of Life: A Report from the ITCH National Registry” and “Temporal and Spatial Patterns of Uremic Pruritis: A Report from the ITCH National Registry.”

Disclosure: Ste. Marie’s employer, Acologix, has a kappa opioid agonist (TRK-820) in clinical development to treat pruritus.