[ Scabies ]

What is Scabies?

Scabies is a skin infestation with a tiny parasite, Sarcoptes scabiei. Scabies is highly contagious and can be transmitted through sexual contact. It can also be spread from nonsexual physical contact with an infected person; hands are a commonly infected area, so even holding hands can spread scabies. Infested bedding, clothing, or even furniture may be a source of infection.

The female mite burrows under the skin and lays 2 to 3 eggs daily. These eggs hatch and become adults within 10 days.

All sex partners and family members of the infected are advised to seek treatment and follow procedures to insure the mites are eliminated from bedding and clothing.

Symptoms

Small red bumps or lines appear where the female mite burrows to lay her eggs. Itching, which is caused by the immature mites, may not develop until a month or so after infestation. This is a problem since an infected person may unknowingly pass scabies to another person with whom he or she has close physical contact. The itching is often worse at night. The areas most commonly affected include the hands, wrists, the bends of elbows and knees, navel, breasts, lower abdomen, and genitals.

Treatment

An effective treatment for scabies is lindane (Kwell). Pregnant or lactating women, people with extensive dermatitis, and children under 2 should not use Kwell. Permethrin (RID; A-200) is a cream that can be used on the body from the neck down. Sulfur is a nonprescription alternative, but is messy and may have an offensive odor. Itching due to the irritation, after treatment, may be relieved with a hydrocortisone cream or ointment.

All sex partners, family members, and persons who have come into close contact with the infected person should be treated to assure the mites have been exterminated. All bedding and clothing should be dry cleaned or washed in very hot water (125° F) and dried at a high setting.

Testing

Since scabies resembles other skin irritations, for an accurate diagnosis, a doctor takes a scraping of the area in question and views it under a light microscope to reveal the presence of the mite, larvae, eggs, or fecal pellets.

The burrow ink test is also used to diagnose scabies. After the tip of a fountain pen is rubbed along the site of a suspected burrow, the ink will penetrate the burrow distinguishing it from the surrounding tissue. This technique is particularly useful in children and individuals with very few burrows.

Topical tetracycline solution is an alternative to the burrow ink test. After the tetracycline solution is applied, a Wood light is then used to examine the burrow. Being a colorless solution, this method is preferred because large areas of skin can be covered.

Retesting after treatment is recommended, but symptoms may persist up to a year even after treatment.