This section of the book is from "The Complete Herbalist" by Dr. O. Phelps Brown. Also available from Amazon: The Complete Herbalist: The People Their Own Physicians By The Use Of Nature's Remedies.
This is caused by an insect by the name of achorion Schonleinii. The eruption takes the shape of large flattened pustules, which have an irregular edge, and are surrounded by inflammation. Sometimes they appear first behind the ears, and at other times upon the face, spreading thence to the scalp. The face is usually involved to some extent wherever the eruption may originally show itself. Scalled head is mostly confined among children. In the outset of the disease the pustules on the scalp are generally distinct: -- on the face they rise in irregular clusters. They are atttended by much itching, and the efforts to relieve this torment hasten their breaking. When broken they discharge a viscid matter and run together, gradually forming sores of a vicious character. These sores are covered by yellowish-greenish scabs which present a revolting appearance.
TREATMENT. -- The hair should be shaved close to the scalp, and the head thoroughly washed with soap and water, after which the zinc ointment should be applied in the morning and the tar ointment in the evening. Alteratives should also be given. This course, if persisted in, will remove the disease.