Seborrheic Dermatitis & Dandruff

Malassezia Yeast Have Key Role

Continuing with our theme this week of fungus, we will focus on seborrheic dermatitis and dandruff. These are extremely common scaly scalp conditions. A fungus known as "Malassezia" is now believed to play a key role in seborrheic dermatitis and dandruff. 
Most human beings are covered in Malassezia. It's just part of being human and living on planet Earth.

Only in a minority of people do these fungi cause any sort of health problems. 
Malassezia were originally discovered by the French scientist Louis Charles Malassez in the late 1800's. There are now recognized to be 14 types of Malassezia. For trivia lovers, Malassezia globosa (mainly) and Malassezia restricta (less so) are the most common causes of seborrheic dermatitis. 

Malassezia are difficult to culture so one can not simply send samples off to the lab. These fungi need fats and lipids to survive - so they live in areas of the body rich in sebaceous (oil) glands such as the scalp and face.

Anti-dandruff shampoos are generally quite effective in killing these fungi. Common ingredients in shampoos include ketoconazole, zinc pyrithione, selenium sulphide and ciclopirox.