This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
This disease consists in an excessive shedding of the scarf-skin in the form of branny scales. It may result from local irritation or general malnutrition. It very frequently affects the scalp, being one cause of dandruff. A peculiar form of the disease, known as pityriasis rubra, or red pityriasis, begins on some part of the body as a red scaly spot, which rapidly extends over the whole surface. The body is intensely red, and covered by scales which fall off in large quantities. The face is also red, as well as other parts of the body, and the head is affected by profuse dandruff.
The latter forms of the affection are relieved by simple inunction of the skin. The skin should be kept constantly covered with some simple unguent, as vaseline, olive oil, or cocoanut oil In the severe form of the affection, the same treatment should be employed, with the addition of daily sponging with water as hot as can be borne.