Background: Pruritus is common in patients with diabetes mellitus (DM), and may lead to complex dermatological conditions if left untreated. Pruritus can be caused by increased transepidermal water loss (TEWL) and reduced skin hydration.
Aims: To compare TEWL and skin hydration in patients with DM and controls, and to investigate associations between TEWL and skin hydration with glycated haemoglobin (HbA1c), fasting blood sugar (FBS), treatment, peripheral neuropathy (PN) and age in patients with diabetes.
Methods: This was a prospective, case-control study carried out at a tertiary medical centre in Kuala Lumpur, Malaysia. TEWL and skin hydration measurements were taken at six different body sites in both groups.
Results: In total, 146 patients (73 cases, 73 controls) were included (24 men and 49 women in each group). No significant difference in TEWL or skin hydration was seen between patients with DM and controls, but there were significant reductions in skin hydration in patients with DM who had FBS > 7 mmol/L (P < 0.01) or PN (P < 0.01). There was a reduction in TEWL over the anterior shin in patients with HbA1c levels > 6.5% (P < 0.02) and an increase in TEWL on the flank in patients on insulin injections at doses of > 1 U/kg/day (P < 0.01). In participants > 45 years old, there was a significant reduction in TEWL (P = 0.04) and hydration (P < 0.04) in the DM and control groups, respectively.
Conclusion: There was no difference in TEWL and skin hydration in patients with DM compared with controls. In the DM group, reduction in skin hydration was associated with uncontrolled FBS and PN but not with HbA1c or DM treatment, whereas TEWL was lower in patients with FBS > 8 mmol/L and increased in patients with higher insulin requirement.
© 2020 British Association of Dermatologists.