Dandruff, simply in broad terms can be taken as smaller pieces of dead skin trapped in a hair.
The death of cell on scalp leads small amount of flaking in most of the individuals. This gets trapped as dandruff. Normal flaking with detergent treatment may be somewhere around 5 lakh/sqcms . In severe cases it may cross more than 8 lakh/sqcms.
Dandruff is common scalp disorder affecting across the globe irrespective of sex, ethnicity and geographic distribution mostly seen in post pubertal age. Seasonal variation has been found with increase in the severity in winter.
Cells of outermost layer of skin called keratinocytes play a major role in immunological reaction in dandruff formation.
It may be result of physiological phenomenon or may be pathological because of certain skin diseases.
It can be caused by unclean scalp or excessive washing of scalp with harsh soaps or shampoo.
Fungal infections, Psoriasis, eczemas, and allergic reactions to the cosmetic products may cause the dandruff.
Excessive production of oil or sebum from sebaceous glands may also play a role in dandruff formation.
In severe case of dandruff, the cell turnover is reduced that is the keratinocytes or the cells of outermost layer of skin gets matured and shed early.
Usually normal flakiness is not associated with any kind of inflammation. If the condition is severe and associated with inflammation then it may be pathological requiring special attention.
Psoriasis is one more common condition mistaken for dandruff most of the times. It is papulosquamous disorder affecting the scalp and beyond. But scalp psoriasis may be present in milder form for quite a long time without affecting the skin. Careful examination and sometimes the biopsy may be required to ascertain the diagnosis.
Allergic reactions to cosmetic products may also present as dandruff, careful history and local examination may reveal the diagnosis.
In most of the times it is fungal infection by malassezia species may be the cause. Excessive sebum production may play role in such infection.
Most of the times mild itching with flakes on the hair may be seen. Severe cases may have discomfort on the scalp. Local examination may have redness on the scalp.
Most of the times it may not cause hair fall, in few studies increase in normal shedding of hair has been noticed with excessive dandruff.
It can be treated with various options that is by using certain medicated shampoos or medicines depending on the cause.