Below are the main rubriks (i.e strongest indications or symptoms) of Petroleum in traditional homeopathic usage, not approved by the FDA.
Eczemas, on scalp, behind ears, scrotum, anus, hands, feet, legs; hands chap and bleed; all worse in winter; get better in summer.
Diarrhoea preceded by colic, only in the day-time.
Headache, or heaviness like lead in the occiput; sometimes with nausea on vomiting; worse by motion, as in riding in boat or carriage.
One of our best anti-psoric remedies. The eruptions that it causes and cures are very similar in appearance to those of Graphites Graphites. They appear on different parts of the body, as scalp, behind ears, on scrotum, female genitals, hands, feet and legs, etc.
There is one very marked characteristic symptom that guides to Petroleum out of a large list having similar eruptions, and that is that the eruption is worse during the winter season (Aloe Socotrina Aloe, Alumina Alumina, Psorinum Psorinum). There is no other remedy that has this so prominently. The hands chap, crack and bleed, and are all covered with eczema during the winter and get well in summer. I hake cured a case of eczema of the lower legs of twenty years' standing, always worse in winter, with one prescription of the 200th. I have cured chapped hands the same way. I once had a very obstinate case of chronic diarrhoea, but as soon as the fact that he had eczema of the hands in winter came to light I cured him quickly of the whole trouble with Petroleum 200th. Chilblains (Agaricus Muscarius Agaricus), which are moist, and itch and burn much in cold weather, are also cured by it. Petroleum; also has a symptom similar to Hep Sulph Calc Hepar sulphuris, viz., the slightest scratch of abrasion of the skin suppurates. You remember that Hepar sulphuris is also worse in cold weather or cold air. Petroleum has headache in the occiput, which is as heavy as lead, also vertigo in the occiput.
Again, Petroleum is one of our best remedies for seasickness. In this it resembles Cocculus Indicus Cocculus. Another curious symptom is cracking of the joints. This is like Causticum Causticum. Both of these remedies are valuable in chronic rheumatism, especially where this symptom is present. Petroleum has, with Chelidonium Majus Chelidonium and Anacardium Occidentale Anacardium, a symptom, pain in stomach, relieved by eating. Again it is valuable in diarrhoea and dysentery, which is worse during the day. Petroleum deserves to be classed with the leading anti-psorics, such as Sulphur Sulphur, Graphites Graphites, Causticum Causticum and Lycopodium Lycopodium.