A portable device using a closed chamber system for measuring transepidermal water loss: comparison with the...

Area of Science:

• Dermatology
• Biophysics
• Skin Physiology

Background:

• Transepidermal water loss (TEWL) measurement assesses stratum corneum (SC) barrier function in vivo.
• Conventional instruments use open chamber systems to measure water vapor pressure gradients.
• A new portable device utilizes a closed chamber system for computed TEWL estimation.

Purpose of the Study:

• To compare the performance of a new portable closed chamber TEWL device with a conventional open chamber method.
• To evaluate the device's ability to assess skin barrier function in healthy and diseased skin.
• To determine the practicality and cost-effectiveness of the new device.

Main Methods:

• An in vivo comparative study was conducted using the new portable device and the DermaLab (conventional method).
• Measurements were performed on healthy and diseased skin under standardized conditions (21°C, 50% RH).
• Statistical analysis was used to compare TEWL values and establish a conversion equation.

Main Results:

• The new device demonstrated sensitivity comparable to the conventional method.
• Significantly higher TEWL values were observed in facial skin compared to extremities, indicating poor SC barrier function.
• Compromised barrier function in atopic dermatitis and psoriasis correlated with disease severity.
• TEWL values from the new device were lower than the DermaLab but showed good correlation (r > 0.8).
• A conversion equation was derived: [DermaLab value] = 1.42 x [Nikkiso-YSI value] + 1.892.

Conclusions:

• The closed chamber system is practical due to its portability and ease of use in any environment.
• The device is less expensive than existing instruments.
• This portable device offers a viable, cost-effective option for in vivo skin barrier function assessment.