Scabies is diagnosed through a physical exam with a doctor.
Scabies is a skin condition caused by Sarcoptes scabiei, a barely visible mite that burrows and lives underneath the skin. This eight-legged arachnid is usually no longer than 0.5 mm. Prolonged, direct contact with an infected person provides opportunities for the mites to transfer. Infestations also spread in households, through shared bedding, clothing, washcloths and towels. Transfer is not likely during quick contact like shaking hands or hugs; nor do pets contract this form of scabies. Individuals with a weak immune system and the elderly are at risk for developing more severe scabies. Fortunately, a topical treatment from a dermatologist or doctor is usually effective in eliminating the mites.
According to John Hopkins Medicine, scabies favor certain body areas, such as wrists, breasts, genital area (typically scrotum and penis), underarms, elbows and between fingers. For children and infants, scabies can emerge on any part of the body, including scalp, head and feet. This condition commonly induces behavioral changes in a child who is experiencing sleeplessness due to intense itching at night.
Male and female mites need to mate only one time for the female to remain fertile throughout her lifecycle. The adult scabies burrow under the skin where the female lays her eggs. Within 3 or 4 days, the eggs hatch and the larvae begin to tunnel underneath the skin. Approximately 4 days later, the larvae enter the adult stage at which point they can transfer to a new host or lay more eggs. With such a short lifecycle, scabies can quickly spread.
Exposure to pets with mange, a condition of animal scabies brought on by a different type of parasitic mite, does not seriously affect people. If mites transfer from a pet to a human, it merely causes itching and irritation for a few days before the mites die.
According to the Centers for Disease Control and Prevention, the rash and itching associated with scabies usually begins between 4 to 6 weeks after contracting the mites. For someone who has contracted scabies previously, symptoms may appear after only a few days. Sores sometimes accompany the itching, leading to the possibility of bacterial infection. Typically, the rash begins with small blisters or red-colored bumps that form thin lines. Each line measures less than 1/8 inch and a close examination sometimes reveals a small black dot at the line's end.
Someone with a severe scabies infestation, involving thousands of mites, often leads to the development of scales or crusts on the infested skin. These symptoms often appear in body crevices.
A visual or a microscopic examination by a doctor confirms the mites presence. Sometimes, a skin scraping is used to identify mites or eggs. However, since most people have fewer than 10 mites, the result can be negative for a person who actually does have mites.
According to the Mayo Clinic, most doctors start treatment by prescribing a lotion or cream, such as permethrin or crotamiton. Permethrin is safe for use on children, however, pregnant women should consult their doctor. The cream or lotion is applied over the entire body, not just affected areas. After 8 hours, or as directed by a doctor, the medication is washed off and clean clothes are put on. This treatment usually kills the mites; however, symptoms like itching may last several weeks. Home remedies, such as an oral antihistamine or over-the-counter calamine lotion, may be effective in relieving itching.
In some cases, a second topical application is needed 7 to 10 days later. If the topical medication doesn't work or the infestation is crusted scabies, a doctor may prescribe an oral treatment of ivermectin. Although avoiding contact with an infected person is the best preventative measure, a doctor may also advise topical treatments for family members and others in close contact with an infested person.
The American Academy of Dermatology warns that scabies can live without a host for 24 hours or more. Therefore, simultaneously treating an infected person's environment is essential to completely eliminating the scabies. Gather all bedding, clothing, towels and other items possibly contaminated by the mites during a 3-day period prior to treatment. Wash everything in hot water and then dry on the high-heat setting. Vacuum carpets and upholstery, and then immediately dispose of the cleaning bag. Seal blankets and other items that cannot be washed in plastic bags for a couple of weeks to kill the parasitic mites.