I often hear people complaining about how their dry scalp causing them dandruff and wanted to be clear about a fact: dandruff is NOT caused by dry scalp, rather by too much oil.
What is dandruff?
Unlike classical seborrheic dermatitis, dandruff is a non-inflammatory condition of the scalp that is characterized by scaling and is considered to be a form of mild seborrheic dermatitis. Dandruff is a common scalp disorder affecting almost half of the post-puberty population regardless of ethnicity and gender. Dandruff occurs when the flakes are large and are accompanied by itching and inflammation.
Although the etiology of dandruff is complex, multifactorial and not fully understood there is a general consensus that it is predicated by the following main factors:
- yeast of the genus Malassezia;
- sebum production;
- various environmental and genetic factors (episodes tending to be worse in early spring and winter, sensitivity to oleic acid).
The levels of Malassezia species on a dandruff-afflicted scalp are more than twice the levels on a normal scalp. Sebum is implicated because the yeast uses it as a feedstock, it multiplies and dandruff appears; so basically oily skin is heaven for this yeast-like fungus.
What is dry scalp?
Well, dry scalp is just dry skin on your head. Unlike dandruff, dry scalp is characterized by small, white flakes of scalp. It can be caused by severe dehydration and over-shedding of the scalp, using poor quality shampoo and conditioner which are stripping your scalp of it’s natural oils, over-washing your hair, washing your hair with hot water, or change in the seasons. Sometimes small flakes can appear as a consequence of building up styling products (certain resins can cause that) or medications like Rogaine. All these can cause flaking and can be easily mistaken for dandruff.
It’s important to understand whether you truly have dandruff or just dry scalp. Then you can decide how to best take care of your scalp; because a healthy hair starts with a healthy scalp.
- Frederik Manuel and S. Ranganathan (2011), A New Postulate on Two Stages of Dandruff: A Clinical Perspective, Int J Trichology. 2011 Jan-Jun; 3(1): 3–6.
- Park HK, Ha M-H, Park S-G, Kim MN, Kim BJ, Kim W (2012) Characterization of the Fungal Microbiota (Mycobiome) in Healthy and Dandruff-Afflicted Human Scalps. PLoS ONE 7(2).