Dermatologist Dr. Sonia Batra answers a viewer's question about the differences between dandruff and dry scalp. Turns out, they are not one and the same!
Dry scalp is due to dryness which results in flakes of skin. Dr. Batra suggests using certain oils or hydrating agents to moisturize the skin. She also says you could take internal omega fatty acids, like flaxseed oil or fish oil.
Dandruff is greasy, red plaques with scales that sometimes itch. This is caused by an overgrowth of yeast, called pityrosporum. In this case, the normal flora of the body's microbiome, when stressed out, sick, or for some other reason, results in an imbalance of the yeast.
It is important to differentiate between these two conditions because if someone uses oils on dandruff, it can actually feed the yeast making the condition worse. For dandruff, anti-yeast agents or over-the-counter shampoos with selenium or zinc will help reduce the yeast count.