Factor analysis approach unveils the influencing factors of dandruff in the normal teenage population.

The aim of this study was to explore the main factors affecting the occurrence of dandruff in healthy people (nondisease-induced scalp desquamation). This study analyzed the fungal microbial diversity of the scalp in Chinese teenage volunteers and measured scalp sebum secretion, the scalp pH value, and scalp transepidermal water loss. The amount and size of dandruff were measured, and the main factors that influence dandruff in the normal population were identified using principal component analysis. The results showed that an increase in Malassezia restricta led to an increased amount of dandruff in the mild and moderate groups. Conversely, this was not found for individuals in the severe group, whose dandruff symptoms were influenced by scalp barrier function. In terms of dandruff area grouping, the pH value and the amount of sebum secretion were the main factors, with the barrier function and microbial diversity being secondary factors. Dandruff cosmetics should emphasize different treatments for different types of dandruff to achieve better antidandruff effects. The results of this study provide a new theoretical basis for the development of multiple targets for antidandruff agents aimed at the normal population.

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.

Assessing therapeutic effectiveness of scalp treatments for dandruff and seborrheic dermatitis, part 2: the impact of gender and ethnicity on efficacy.

BACKGROUND: Dandruff and seborrheic dermatitis (D/SD) are common and troublesome scalp conditions that affect individuals independent of gender or ethnicity. AIM: To evaluate whether population gender or ethnic origins impact the magnitude of anti-dandruff therapeutic benefit obtained from use of a potentiated zinc pyrithione shampoo treatment. METHODS: A retrospective evaluation of anti-dandruff clinical data covering a single-product technology was conducted to assess whether statistically meaningful differences were observed for gender or ethnic sub-populations. An analysis of covariance was performed on the pooled subject-level data. RESULTS: Meta-analysis of clinical data involving 1114 subjects from seven trials demonstrated the lack of statistically significant impact of gender on flaking or selected biomarker measures. Similarly, a smaller population chosen to assess ethnicity demonstrated the lack of differences between Asian and Caucasian clinical sub-population responses (flaking severity). CONCLUSION: Through the use of both expert symptom grading and objective biomarker assessments, therapeutic efficacy of a potentiated zinc pyrithione shampoo was found to be independent of gender and ethnicity, being consistent with the lack of functional differences in skin from these populations.