What is the main cause of seborrheic dermatitis?

Seborrheic dermatitis is primarily associated with the presence of Malassezia yeast, which is a type of fungus that naturally inhabits the skin. This yeast thrives in areas with a high concentration of sebaceous (oil) glands, such as the scalp, face, and upper body. An overgrowth of Malassezia can lead to inflammation, disrupting the normal skin barrier and resulting in the characteristic symptoms of seborrheic dermatitis, including redness, scaling, and flaking.

While factors like excessive sun exposure, allergic reactions, and genetic predispositions can influence the severity or onset of skin conditions, they do not serve as the primary cause of seborrheic dermatitis. It’s the imbalance of the Malassezia yeast and the skin’s response to it that primarily drives this condition.