Natural (Mineral, Vegetable, Coconut, Essential) Oils and Contact Dermatitis.

Natural oils include mineral oil with emollient, occlusive, and humectant properties and the plant-derived essential, coconut, and other vegetable oils, composed of triglycerides that microbiota lipases hydrolyze into glycerin, a potent humectant, and fatty acids (FAs) with varying physico-chemical properties. Unsaturated FAs have high linoleic acid used for synthesis of ceramide-I linoleate, a barrier lipid, but more pro-inflammatory omega-6:-3 ratios above 10:1, and their double bonds form less occlusive palisades. VCO FAs have a low linoleic acid content but shorter and saturated FAs that form a more compact palisade, more anti-inflammatory omega-6:-3 ratio of 2:1, close to 7:1 of olive oil, which disrupts the skin barrier, otherwise useful as a penetration enhancer.