Scabies is a parasitic sexually transmitted disease (STD) caused by a burrowing mite of the species Sarcoptes scabiei. The scabies mite makes distinctive red lines on the skin as it burrows underneath it to lay its eggs. In addition to the red lines, the most notable symptom of scabies is the intense itching. This is a natural allergic reaction of the body to the scabies mite and its feces. Scabies is primarily spread through sexual or other close contact, and occurs most often in the genitalia. The scabies mite will also sometimes do its damage in the breasts, abdomen, buttocks, wrists, fingers, thighs, or ankles. Scabies is fully curable with a topical pesticide. This generally comes in the form of a cream, which is spread over the body from the neck down for a specified period of time, and then washed off. There are over-the-counter scabies treatments with the chemical permethrin that people have used for many years with some success, sold under brand names including Rid and Nix. However, no such over-the-counter scabies treatment has been formally tested and declared effective for the treatment of scabies by the Food and Drug Administration.
Therefore, the Centers for Disease Control and Prevention (CDC) recommends that prescription-strength treatments instead be obtained and used against scabies.
Some of these prescription treatments also contain permethrin, but in higher concentrations than are sold over-the-counter. Others contain the chemical lindane, a similar scabicide. For babies and people who are sensitive to these chemicals, physicians may prescribe a non-chemical treatment with crotamiton. For people with weakened immune systems and for people who do not respond to these treatments, the oral medication ivermectin is sometimes prescribed.
Because scabies is so easily transmitted, and because it can take weeks from the initial infestation for it to manifest itself, the CDC recommends that when a person is treated for scabies, their intimate partners and anyone else living in their household also be treated. Furthermore, because the scabies mite can live for short times on inanimate objects, the CDC also recommends that bedding, clothing, and towels used by anyone who is or might be infested be treated. These items should be washed in hot water and dried in a hot dryer, dry cleaned, or sealed in plastic for at least three days.
Even when the correct treatment is followed, relief may take awhile. The allergic reaction and the itch can persist for days or weeks even after the last of the scabies mites are gone.
“Scabies.” Centers for Disease Control and Prevention
“Scabies.” Mayo Clinic