If you spill diluted essential oil onto your skin, in most cases, this should not cause any problems, especially if you have carried out a patch test before applying the oil to your body. Dealing with undiluted essential oils is slightly different, as they are more concentrated and can cause allergic reactions and skin irritation if they come into contact with your skin. If it happens directly or via a piece of clothing you are wearing or piece of furniture you have touched, you should respond in the same way. Use soap and warm water to wash it off your skin. If redness or irritation continues, apply some coconut oil or jojoba oil to soothe the area. Topical or antihistamine medications can also help if itching persists. You may want to consult your doctor if you continue to experience issues after washing the oil off your skin.