Psoriasis, a skin health condition can be characterised by the rapid and increased expansion of skin cells that can result in red, thick skin patches that are scaly. The most frequent type of psoriasis that affects many people suffering from psoriasis. It is a problem for the scalp and may extend into the forehead, behind the neck and the area behind your ears. The condition may vary in severity, with slight, moderate scaling or large, crusty plaques that cover the entire scalp in more severe instances.