EADV 2021 A Selenium Disulfide-based shampoo improves significantly severe Dandruff and Seborrheic Dermatitis: results from a large international observational study

INTRODUCTION

Dandruff is a milder form of seborrheic dermatitis (SD), a chronic and relapsing inflammatory condition of the scalp, face and upper chest. Conversely to SD presenting with erythema, scaling and frequent pruritus, dandruff goes mainly along with flakes only and does not show any visible signs of inflammation. Malassezia yeasts have been suggested to be key actors in dandruff/SD At the species level, M. restrict and M. globosa are the most frequently observed species on healthy scalp. Specific strains of M. restricta have been identified to be associated with dandruff/SD. The ability of Malassezia spp. to metabolize and oxidize sebum-derived lipids into inflammatory compounds and to produe indole derivatives including malassezin and indolocarbazole with an activity against aryl hydrocarbon receptors might trigger skin inflammation. Moreover, certain Malassezia spp., especially M. restricta, have been reported to be able to induce cytotoxicity to skin cells in vitro suggesting an active role in accelerated scale formation.
Selenium disulfide (SeS) is effective in managing both dandruff and SD. It reduces flake, itching, irritation and redness of the scalp. It has shown a full spectrum antimicrobial action against Malassezia yeasts and bacterial species.
SeS has been combined with salicylic acid, tocopherol and ceramides in the tested cosmetic shampoo (SeS-based shampoo).