Which fungus is associated with causing dandruff, also known as pityriasis?

Malassezia is the correct fungus associated with causing dandruff, also known as pityriasis. This yeast is a normal inhabitant of the scalp but can become pathogenic under certain conditions, leading to an overgrowth that results in dandruff. The overproduction of skin cells and an inflammatory response to these yeast organisms contribute to the flaking and itching commonly experienced with dandruff.

Malassezia thrives in oily environments, which is why dandruff is more prevalent in individuals with oily scalps. Its presence disrupts the balance of skin flora, leading to irritation and an increase in the turnover of skin cells. Recognizing the role of Malassezia can help in selecting appropriate treatments, such as those containing antifungal agents, to effectively manage and reduce dandruff symptoms.

Other fungi listed, such as Trichophyton and Microsporum, are primarily associated with different forms of fungal infections like ringworm, while Aspergillus is more commonly linked to respiratory issues and does not have a role in dandruff development.