How Is Scabies Transmitted?

Scabies

Scabies (Sarcoptes scabei) are small mites, barely visible to the naked eye. They live and breed on human skin and feed on human blood. Scabies mites are transmitted between humans and do not infect pets---it is a different type of mite that infects animals. The symptoms of scabies include severe itching, especially at nighttime, and a rash that looks like allergic contact dermatitis or small red bumps. The itching results from toxins released by the mites, which causes an allergic reaction in humans.

Prevalence

Scabies is very common, affecting 300 million people around the world each year, according to the American Academy of Dermatology. It is most common in crowded environments where frequent close contact occurs between large groups of people. Immune-compromised individuals and people who live under poor hygiene conditions tend to get more severe scabies infections.

Close Contact

Prolonged close contact with an infected person is generally required to contract scabies. Scabies is sometimes referred to as a sexually transmitted disease since sexual activity is a possible mode of transmission. Technically, scabies is not a sexually transmitted disease because it can be passed through non-sexual forms of close contact, such as holding hands, sharing clothes, cuddling on the couch or sleeping in the same bed.

Quick Contact

Scabies usually requires prolonged contact for transmission, with the exception of Norwegian scabies. Norwegian scabies is a more series infection that can be spread by quickly brushing up against an infected person, according to the Centers for Disease Control and Prevention (CDC). Norwegian scabies is also called crusted scabies, because the infected person develops crusty patches of skin due to the high number of mites living in the skin.

Clothing, Bedding and Furniture

Clothing, bedding, furniture and carpet can become infected with scabies when used by an infected person. Scabies can survive on inanimate objects for up to three days.

When Symptoms Develop

When scabies is transmitted to a new person, a female scabies mite burrows into the new person's skin and lays eggs. After 21 days, the eggs hatch. The hatched eggs hide on the person's skin, mature and eventually breed. The matured female mites burrow into the skin to lay eggs and the cycle continues. Itching symptoms may be noticed relatively soon after infection, but may not be noticed until after the mites hatch and a full-blown infection develops.

Treatment

Treatment for scabies involves the application of a topical cream or oral medication in advanced cases. Over the counter scabies medications are available, but their effectiveness and safety are not known. The CDC warns that "no "over-the-counter" (non-prescription) products have been tested and approved to treat human scabies."