Assessment of Skin Properties in Chronic Lymphedema: Measurement of Skin Stiffness, Percentage Water Content, and Transepidermal Water Loss

Ziyou Yu, PhD, Ningfei Liu, PhD, Li Wang, BS, Jiajia Chen, BS, Linghua Han, BS, and Di Sun, PhD. Lymphatic Research Biology 2019.


Background: Lymphedema (LE) is a chronic progressive protein-rich edema of the soft tissues. Measurement of extracellular fluid of the affected limbs is widely used in detecting LE; however, quantification of the skin alterations and early tissue changes in LE lacks approaches.

Methods and Results: Ninety-one patients with LE were assessed. Measurement of transepidermal water loss (TEWL), skin stiffness (SF), and percentage water content (PWC) was assessed on five predetermined skin sites. The value of TEWL, SF, and PWC increased significantly in lymphedematous skin compare with controls, indicating damaged function and texture of the affected skin. Both PWC ratio and SF ratio strongly correlated with LE stage. High correlations were found among instruments assessing tissue fluid.

Conclusions: Assessment of the skin parameters has contributed new information about the functional and structural alterations in chronic lymphedematous skin. Quantification of skin properties changes could be a valuable supplement to diagnosis and evaluation of chronic LE.

Main findings

  • N= 90 women
  • Measurements included:
    • Bioelectrical impedance analysis ECF
    • Skin stiffness (SF)
    • Tissue dielectric constant (TDC) measurement – Lymphscanner (Delfin) was used.
    • Transepidermal water loss (TEWL) reflect epidermal permeability barrier function. This was measured by the VapoMeter (Delfin)
  • A total of five sites were measured. At the dorsal midline across the first web space of the hand, as well as the anterior and posterior midline across the mid upper arm and forearm level of the upper limb; at 5cm above the second plantar toe joint, as well as the lateral midline across the midthigh and calf level of the lower limb.
  • Both the value of ECF measured by BI analysis and the value of PWC measured by LymphScanner reflect the extent and amount of fluid accumulation. Although these two values are significantly increased in lymphedematous limb, strong correlations were found between LE stage with ECF ratio but not PWC ratio, whereas compared with ECF ratio, PWC ratio showed a higher value in stage I (16.57%) and stage II (33.40%) LE, but the value increased less obviously in late stage LE.
  • This could be explained by the progressive accumulation of the fluid with increased severity of LE. In early stage of edema, the accumulation of lymphatic fluid begins at the skin dermis, which could be accurately detected by LymphScanner with a sensitive probe of a measurement depth up to 2.5mm. With progression, fluid accumulation extends from the dermis to deep fascia, leading to greatly increased the thickness of the skin and subcutis, which might be beyond the maximum measurement depth of the probe and thus unable to reflect the severity of late-stage LE.
  • Compared with LymphScanner that measures PWC of a certain layer of the tissue, BI analysis measures the ECF change in the whole limb, thus could be more suitable in reflecting the severity and progression of the disease.
  • Chronic inflammation and progressive fibrosis are characteristic pathological features of LE. SF value is accurate and reliable for the evaluation of skin fibrosis. Measurement and analysis of SF showed increased SF value with increasing severity of LE.
  • On clinical examination, patients with chronic LE often have dry hyperkeratotic skin, especially in advanced stage LE.23 TEWL, an indicator of skin barrier function, which was measured with VapoMeter. TEWL value increased significantly in lymphedematous skin, which indicates an impaired skin barrier system due to long-term lymph stasis. The compromised skin barrier function may result in increased risks of skin irritation, sensitization, or infection in the affected limb. The TEWL ratio tends to increase with disease severity, although the correlation between TEWL and stage of LE or the ECF value was weak. This might be due to the high interindividual variability of TEWL parameter.
  • Quantification of skin changes in chronic LE provides diagnostic valuable information of the skin condition in the affected limb. Further studies on the assessment of skin properties in LE after complex decongestive therapy or lymphatic surgeries should be considered.