Abstract / Summary
Background: Routine hair drying delivers convective heat to the scalp, which is rarely an endpoint in dryer evaluation; flaking scalps may be particularly vulnerable.This exploratory study evaluated immediate scalp responses to a low-temperature, airflow-controlled drying mode vs. constant hot-air drying, with supporting ex vivo assessments.Methods: Twenty-three females aged 30-59 years with visible scalp flaking underwent capacitance hydration, desquamation index, and CIELAB a* measurement before and immediately after a single use of the in vivo test mode (constant 60°C damage-care setting, three-path shaped airflow) and of a conventional mode (constant 80°C), each applied at a separate visit in a fixed, nonrandomized sequence.In the ex vivo component, 40 Asian virgin-hair tresses received a warm-cool alternating test mode (60°C-80°C) or the conventional mode (n = 20 each) for polarization-imaging luster and post-induction flyaway area.Results: Scalp hydration readings rose by 67.0% vs. 29.5% (test vs. conventional mode); the desquamation index fell by 17.5% vs. 8.8%; and a* fell by 8.0% under the test mode but rose by 4.5% under the conventional mode.Mode-by-time interaction p-values were <0.001, 0.041, and 0.026, respectively (unadjusted exploratory analyses).In the ex vivo hair assessments, luster rose by 6.7% vs. 1.0%, and flyaway area was 36.0%lower.Conclusion: Across the in vivo scalp and ex vivo hair components, the respective test modes were associated with immediate instrument-recorded responses in a more favorable direction than their respective conventionalmode comparators; the consistent direction across endpoints, rather than any single p-value, is the principal exploratory finding.