A Comprehensive Pathophysiology of Dandruff and Seborrheic Dermatitis – Towards a More Precise Definition of Scalp Health
James R. Schwartz, Andrew G. Messenger, Antonella Tosti, Gail Todd, Maria Hordinsky, Roderick J. Hay, Xuemin Wang, Claus Zachariae, Kathy M. Kerr, James P. Henry, Rene C. Rust, Michael K. Robinson
Despite an increasing knowledge of dandruff and seborrheic dermatitis (D/SD), the pathophysiological understanding is still incomplete but suggests a role of Malassezia yeasts in triggering inflammatory and hyper-proliferative epidermal responses. The objective of this report is to review published literature from in vivo studies of D/SD populations to provide a more complete description of overall scalp health. New biomolecular capabilities establish a depth of pathophysiological understanding not previously achievable with traditional means of investigation. Biomarkers representing inflammation, hyper-proliferation and barrier function are all perturbed by the D/SD condition and robustly respond to therapeutic resolution. These biomarkers can be sampled noninvasively, enabling their use in routine clinical evaluations as either surrogate endpoints or complementary ones to classical signs/symptoms to broaden the etiological learning.