EADV 2021 Comparison of the benefit of a Selenium Disulfide-based shampoo and a shampoo containing Zinc Pyrithione in the management of moderate to severe dandruff

INTRODUCTION

Seborrheic Dermatitis (SD) is a chronic and relapsing inflammatory skin condition of sebum-rich areas such as the scalo. It is characterized by erythema, mild to moderate scaling resulting in greasy and flaky scalp, and is sometimes associated with pruritus. In the adult population its prevalence is up to 5 %, with a higher prevalence in immunocompromised patients and in patients with neurologic diseases. When only mild scaling without visible inflammation is observed, scalp SD is called dandruff (D) and up to 50% of the population suffer from dandruff. Various environmental, intrinsic and host immune factors may contribute to the development of SD, leading to an alteration of the sebaceous gland activity and sebum composition, epidermal barrier function, and skin surface fungal colonization, which ultimately leads to inflammation. Among these factors, lipophilic Malassezia yeasts may play a key role.
Zinc pyrithione (ZPT) has been reported to be active against Malassezia spp. yeasts. It inhibits M. restricta and significantly reduces the expression of lipases, whose activities contribute to the survival and virulence of M. restricta on human skin.
Selenium disulphide-based shampoo (SeS) is an effective means in the treatment of dandruff, a milder form of seborrheic dermatitis. SeS has antifungal properties against Malassezia spp. and also inhibits Staphylococcus epidermidis growth in vitro. Moreover, the SeS-based shampoo contains salicylic acid, known for its keratolytic activity, allowing to reduce flakes on the scalp.