Assessing therapeutic effectiveness of scalp treatments for dandruff and seborrheic dermatitis, part 1: a reliable and relevant method based on the adherent scalp flaking score (ASFS)

Background: Dandruff and seborrheic dermatitis (D/SD) are common and troublesome scalp conditions with the primary signs and symptoms being presence of skin flakes, pruritus, a tight feeling, and sometimes erythema. Aim: To demonstrate the reliability and relevance of a clinical model for the assessment of therapeutic efficacy of a treatment using the Adherent Scalp Flaking Score (ASFS) method to quantitate the flaking severity. Methods: Six randomized, double-blind, parallel design studies were conducted in either North America or Asia with subjects suffering from dandruff using the ASFS grading method before and after a 3-week test product treatment period. Results: Treatment with a commercial potentiated 1% zinc pyrithione (ZPT) shampoo resulted in statistically significant (p < 0.0001) improvements in total ASFS compared with the placebo cosmetic shampoo. Results were consistent across all studies, geographies, and product usage protocols (controlled on-site versus home use conditions), and were associated with statistically significant improvements in self-perception of scalp condition. Conclusion: The ASFS-based clinical model was demonstrated to be a reliable and proven methodology to assess the effectiveness of widely used anti-dandruff treatments. The results are consistent with patient self-assessments, establishing this methodology as relevant to patient perception of product benefits.