Scabies (cont.)

Scabies is suggested by the presence of the typical rash and symptoms of unrelenting and worsening itch, particularly at night. Ultimately, the definitive diagnosis is made when evidence of mites is found from a skin scraping test. By scraping the skin (covered with a drop of mineral oil) sideways with a scalpel blade over an area of a burrow and examining the scrapings microscopically, it is possible to identify mites, eggs, or pellets. This process can be difficult, however, since burrows can be hard to identify. Sometimes scratch marks are mistaken for burrows, and even the examination of scrapings from 15 or more burrows may only reveal one or two mites or eggs. If the characteristic physical findings are present, scabies can often be treated without performing the skin scrapings necessary to identify the mites.

Curing scabies is rather easy with the administration of prescription scabicide drugs. There are no approved over-the-counter preparations that have been proved to be effective in eliminating scabies. The following steps should be included in the treatment of scabies:

1. Apply a mite-killer like permethrin (Elimite). These creams are applied from the neck down, left on overnight, then washed off. This application is usually repeated in seven days. Permethrin is approved for use in people 2 months of age and older.
2. An alternative treatment is 1 ounce of a 1% lotion or 30 grams of cream of lindane, applied from the neck down and washed off after approximately eight hours. Since lindane can cause seizures when it is absorbed through the skin, it should not be used if skin is significantly irritated or wet, such as with extensive skin disease, rash, or after a bath. As an additional precaution, lindane should not be used in pregnant or nursing women, the elderly, people with skin sores at the site of the application, children younger than 2 years of age, or people who weigh less than 110 pounds. Lindane is not a first-line treatment and is only recommended if patients cannot tolerate other therapies or if other therapies have not been effective.
3. Ivermectin, an oral medication, is an antiparasitic medication that has also been shown to be an effective scabicide, although it is not FDA-approved for this use. The CDC recommends taking this drug at a dosage of 200 micrograms per kilogram body weight as a single dose, followed by a repeat dose two weeks later. Although taking a drug by mouth is more convenient than application of the cream, ivermectin has a greater risk of toxic side effects than permethrin and has not been shown to be superior to permethrin in eradicating scabies. It is typically used only when topical medications have failed or when the patient cannot tolerate them.
4. Crotamiton lotion 10% and cream 10% (Eurax, Crotan) is another drug that has been approved for the treatment of scabies in adults, but it is not approved for use in children. However, treatment failures have been documented with the use of crotamiton.
5. Sulfur in petrolatum applied as a cream or ointment is one of the earliest known treatments for scabies. It has not been approved by the FDA for this use, and sulfur should only be used when permethrin, lindane, or ivermectin cannot be tolerated. However, sulfur is safe for use in pregnant women and infants.
6. Antihistamines, such as diphenhydramine (Benadryl), can be useful in helping provide relief from itching. Sometimes, a short course of topical or oral steroids is prescribed to help control the itching.
7. Wash linens and bedclothes in hot water. Because mites don't live long away from the body, it is not necessary to dry-clean the whole wardrobe, spray furniture and rugs, and so forth.
8. Treat sexual contacts or relevant family members (who either have either symptoms or have the kind of relationship that makes transmission likely).

Just as the itch of scabies takes a while to reach a crescendo, it takes a few days to subside after treatment. After a week or two, relief is dramatic. If that doesn't happen, the diagnosis of scabies must be questioned.

Source: MedicineNet.com
http://www.medicinenet.com/scabies/article.htm