Hawaii Esthetician State Board Exam 2025 – 400 Free Practice Questions to Pass the Exam

TEWL, or Transepidermal Water Loss, primarily relates to the skin's function of protection. It describes the process by which moisture is lost from the skin's inner layers to the external environment. This moisture loss is critical because the skin acts as a barrier that protects underlying tissues from external aggressors such as pathogens, pollutants, and irritants.

The ability of the skin to retain moisture is essential for maintaining its barrier function. When the skin is compromised, it can lead to increased TEWL, making it more susceptible to infection and inflammation. Therefore, managing TEWL through effective skincare and barrier reinforcement is vital for preserving the skin’s protective capabilities.

While the other options—secretion, thermoregulation, and excretion—do play roles in skin function, TEWL specifically highlights the importance of the protective role that maintains skin hydration and overall health.