According to Ayurved it could be pitta problem because pitta governs the skin. If you are eating pitta-increasing foods like vinegar, hot peppers, cheese, etc., this would increase sensitivity of the skin. It could also be a reaction to the ingredients in the oil, which again might mean oversensitivity of the skin or simply the wrong herbs in the oil. Ayurvedic oils come from a long proven tradition of knowledge of herbs; I would stick with Ayurvedic oils only.