The treatment for parasitic skin infections depends on the type of parasite involved. Some are treated with both prescription and over-the-counter medications. But for others, like scabies, physicians start with a topical cream to kill the parasites in the affected area. Getting rid of the infestation is important. For lice, treatment is focused on getting rid of the lice on the body and in clothes and bedding. In the case of swimmer's itch, medical treatment is usually unnecessary. But over-the-counter drugs and treatments, such as colloidal oatmeal, Epsom salts, or baking soda, may be used to ease the itch, as may cool compresses. Calamine lotion is also recommended. Ask your healthcare provider. For those infestations that are more serious and are not responding to topical medications, your physician may prescribe oral medications, such as ivermectin for scabies or lice.