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.
§ 161. C. Rheumatism of the thorax. The affection is generally seated in the pectorales, less frequently in the intercostales muscles. The pain is generally sticking or tearing in one part of the chest, generally only on one side, rarely on both sides at the same time; it is aggravated by deep breathing when the intercostal muscles, and by stooping and pressure when the pectoral muscles are affected. Cough, and the physical symptoms of pleuritis and pneumonia are entirely wanting, except when the rheumatism seizes the pleura, which is sometimes the case. There is generally very little fever, and scarcely ever critical sweat or urine.
§ 162. Bryonia and Arnica are generally indicated, seldom Aconite. Arnica should be given when the external muscles are alone affected, sensitive to pressure and sore, particularly when the affection arises from some mechanical cause and the body feels bruised and languid. Bryonia is useful when both the external and intercostal muscles are affected. Bellad., Nux vom., Rhus t., Squilla, Sabad., may likewise be useful. For rheumatic pleuritis or pleuro-pneumonia, use the remedies indicated for those diseases.