Iodine should not be applied to wounds. Iodine contains iodine as well as alcohol, which is a mixture of the two, and its internal concentration of iodine is relatively high, and alcohol is also irritating to wounds, so iodine should not be applied to wounds. Iodine is a disinfectant and antiseptic for the skin, and has the effect of killing bacteria, fungi and spores. However, iodine is usually used when the skin surface is intact, that is, when there is no wound on the skin, and after disinfection with iodine, alcohol is used twice to de-iodize the skin. Because iodine deposited on the skin for a long time may cause allergic reactions, may also lead to hyperpigmentation, etc..