DIAGNOSIS METHODS FOR SCABIES
The diagnosis of scabies is very difficult clinically. Many types of primary and secondary scabies lesions differ from the classic burrows. For example, scabies can present as pearly vesicles with underlying inflammation, red papules, pustules, secondarily infected crusted lesions, nodules, eczematous patches and urticarial wheals.
Generally the diagnosis is made by finding scabies burrows. However these scabies burrows are difficult to find as they are very scarce as they are obscured by scratch marks, or by secondary dermatitis. If burrows are not found in primary areas known to be affected, the entire skin surface of the body should be examined.
A scraping of the skin can reveal the presence of mites, mite eggs or mite feces when the skin sample is examined under a microscope.
The scabies preparation is a simple office test. It has many advantages, including simplicity, low cost, readily available equipment, rapidity and high sensitivity when multiple areas are tested. An alternative test for scabies is skin biopsy. The time required to perform a biopsy, the expense, the delay in diagnosis while the tissue is processed and patient discomfort are all drawbacks to using a biopsy for diagnosis of scabies.
The best approach is to paint the selected areas of involved skin with blue-black fountain pen ink. Any apparent scabies burrows or papules should be inked. A drop of oil is placed on the skin overlying the “inked” burrows, and a drop of oil is placed on a glass microscope slide. The inked area is scraped with a scalpel blade, collecting oil, scale and debris.
The area is scraped until the burrow is unroofed and the ink and the contents of the burrow have been removed. Multiple scabies lesions are scraped. Subungual debris can also be scraped. Since the burrow is in the outer layer of the skin, no significant bleeding occurs during the procedure. The specimen is then examined under low power to identify mites.
Alternative diagnostic methods such as KOH preparation, stripping with cellophane tape, needle extraction and topical tetracycline and a Wood’s lamp have been described.
Treatment and prevention for scabies
Patients are normally offered dangerous pesticide-laced lotions or creams to be applied regulary as prescribed by the dermatologist. Also malathion, sulfur ointment and lindane are also used for treatment of scabies.
A better alternative is using all-natural, non-toxic ingredients such as are found in Scabies-Killer products.
Patients are also advised to wash any items they are in contact with in hot, soapy water. The items should be dried in high heat. Dry cleaning is another alternative. Also the house should be vacuumed and the items that are not washable should be stored in sealed plastic bags for at least two weeks. This will starve and kill any scabies mites on these items.