Dandruff is defined as the shedding of dead scalp skin cells
exceed normal cell normal flaking. A small amount of flaking is
common most of which is invisible to the naked eye and is washed
away when we wash our hair. However, with dandruff, the skin
cell turnover is unusually rapid (up to 8-10 times faster) and
visible due to the cells clumping with oil before they shed. In
addition, when the shedding is accompanied by redness and
irritation it is more likely to be dandruff. Triggers to an
outbreak of dandruff include exposure to extreme hot and cold
(hot showers in winter) but the underlying cause is the result
of a combination of factors including the overgrowth of skin
microorganisms known as Malassezia globsa, a fungus that is
normally present on the skin surface of the scalp. Malassezia
interacts with components in sebum creating and inflammatory
response in the scalp of susceptible persons which results in
excessive shedding of the top layer of the skin. Extremes in
temperature such as hot showers in c