Dandruff is mostly related to fungi.
Dandruff consists of cells in the stratum corneum of the scalp. Under normal circumstances, the cells in the basal layer under the scalp epidermis will continue to multiply and push out to the surface, and when these cells mature into the stratum corneum, they will fall off. Generally speaking, it takes about 28 days for scalp keratinocytes to fall off. On the scalp, there is also a common fungus group called Malassezia, which feeds on the sebum secreted by the scalp. If the reproduction of Malassezia is abnormal and the number exceeds the normal level, the metabolism of epidermis will be accelerated, and the shedding process of keratinocytes will be compressed to 7~2 1 day. Epidermal cells will fall off in large groups, which is dandruff visible to the naked eye. In addition, Malassezia can destroy the tight structure of scalp keratinocytes and intercellular lipid layers, making the scalp itchy and sensitive.
There are many factors of scalp itching.
Scalp itching is usually a comprehensive factor, such as fungal infection (dermatophytes), environmental impact, climate change, mental stress, improper hair dyeing or shampoo products and so on. Greasy hair and itchy scalp can affect each other. Greasy hair can form a suitable growth environment for fungal infections (such as dermatophytes), and the propagation of fungi further leads to scalp itching and dandruff.
Winter is the season of high incidence of respiratory infectious diseases, mainly influenza, meningitis, mumps, me