The Role of the Scalp Microbiome in Health and Pathogenesis

“Dandruff” is a common name describing flaking and itching of scalp, resulting in white flakes on the hair or clothing. Severe dandruff is referred to in the clinical establishment as seborrheic dermatitis.  More than 50% of adults are afflicted, leading to direct, indirect, and intangible costs exceeding $20 billion USD in 2012.  The anti-dandruff shampoo business alone is >$10 billion USD per year.  Dandruff research is in the midst of a resurgence, reinvigorated by the discovery of the causal fungal species (Malassezia globosa and restricta) and recent availability of multiple complete Malassezia genomes.