This section is from the book "Hartmann's Theory Acute Diseases And Their Homoeopathic Treatment", by Charles J. Hempel. Also available from Amazon: Theory of acute diseases, and their homoeopathic treatment.
§ 107. Complications of scarlatina, with other diseases.
Now-a-days the genuine scarlatina generally occurs in combination with purple-rash. The eruption is sometimes attended with gastric symptoms, the fever being either erethic or a real synocha accompanied with vomiting. In this case Aconite should at once be given, particularly if the heat, restlessness and anxiety increase from hour to hour. Although the fever is moderated by Aconite, yet the inflammatory character of the angina increases with the progressive development of the exanthem, and requires Belladonna, Mer-curius, Dulcamara, Baryta, as its specific remedies.
If the fever should set in from the commencement as an erethic fever, without any striking morbid symptoms, Belladonna is indicated. But if the fever should exacerbate in the evening, with nausea, vomiting, whining mood, moaning, it is proper to give a few doses of Ipecacuanha before Belladonna. The excessive pain and the whining mood require sometimes to be controlled by a few doses of Coffea cr., particularly if the patients are very sensitive.
This eruption is more or less dangerous even under homoeopathic treatment, inasmuch as it excites many morbid tendencies which had been latent in the organism, and, by so doing, becomes frequently fatal. The symptoms indicate Belladonna, though it is given without effect. The best remedy for that group of symptoms is generally Sulphur; in some cases Ammon, carb., Sepia, Lycop., Canthar., Arsen., are more suitable.
The exanthem is sometimes accompanied with encephalitis, which often leads to acute hydrocephalus. In this case Belladonna is the appropriate remedy, particularly when the patient is lying in a state of stupid unconsciousness, as if paralyzed, alternating with wild starting and cries which seem to be occasioned by colicky pains in the abdomen; after the spasms have subsided, Mercurius, Arnica, Digitalis, Arsenic, Hyoscyam., Sulphur, Rhus t. are frequently useful.