Multifactorial causes of chronic itch in diabetes: More than just neuropathy

Chronic pruritus is common in patients with diabetes though its pathophysiology is unknown and difficult to pinpoint given the multi-system manifestations of diabetes. Herein, we aim to evaluate the severity of chronic itch in patients with diabetes and its association with glycaemic control, microvascular complications and quality of life.

We conducted a retrospective study of 105 adults with diabetes evaluated by a dermatologist at a tertiary care centre in Mexico City. Degree of chronic pruritus and its impact on quality of life as well as laboratory, clinical and demographic data were collected. Patients without chronic pruritus (n = 62) were compared to those with chronic pruritus (n = 43). The latter cohort was further stratified by itch severity, and characteristics of their itch were quantified.

Neuropathy and loss of protective sensation were more common in patients with chronic pruritus, compared to those without chronic pruritus (p = 0.007 and p = 0.001, respectively). Anxiety and depression were more common in individuals with chronic pruritus (p = 0.009), and these group reported higher effect of pruritus on their quality of life (p < 0.0001). The most common sites of itch were the head, back and arms. Among patients with chronic itch, increasing itch severity was associated with decreasing eGFR (p = 0.080).

The underlying cause of chronic itch in patients with diabetes is likely multifactorial and owing to microvascular complications such as neuropathy and nephropathy. Better understanding of the causes of itch in these patients can allow for more targeted treatment, leading to improved quality of life.