Scabies Symptoms, Signs, Treatment Facts and Information on MedicineNet.com

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Medical Authors: Alan Rockoff, MD and Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

What Is "Norwegian Scabies"?

Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR

Norwegian scabies is sexually transmitted disease that causes an itchy skin rash. Scabies is a well-known infection that results in a particularly relentless and devastating itch that starts out slowly and increases in severity over time. The mites that cause the condition, scientifically known as Sarcoptes scabiei, burrow into the skin of infected humans. While they are so tiny that it's not possible to see them with the naked eye, they can be appreciated by examination with a magnifying glass or microscope.

Sometimes, doctors or others health-care providers may refer to "Norwegian" scabies, and this term can be confusing. The name seems to imply that the condition is caused by a specific type of mite that is found in Norway or that preferentially affects people of Norwegian descent, neither of which is true. The term "Norwegian scabies" refers instead to a particularly severe form of scabies that is also known as crusted scabies. Crusted scabies has been called Norwegian scabies because the condition was first described in Norway in the mid-19th century.

Garden-variety scabies produces small bumps and blisters in the webs between the fingers, on the wrists, the backs of the elbows, in the groin, on the knees, and on the buttocks. Men sometimes get what look like pimples on their penis. The infection is transmitted by any close contact, including sexual contact, so scabies is considered to be one of the sexually transmitted diseases. In otherwise healthy people, not every bump on the skin is a bug. In fact, in most cases of scabies in healthy adults, there are no more than 10 or 15 live mites on the skin even if the infected person has hundreds of bumps and pimples.

Get the facts on Norwegian scabies »

What is scabies?

Scabies is an itchy skin condition caused by an infestation by the itch mite Sarcoptes scabiei. Mites are small eight-legged parasites (in contrast to insects, which have six legs). They are tiny, just 1/3 millimeter long, and burrow into the skin to produce intense itching, which tends to be worse at night. The mites that cause scabies are not visible with the naked eye but can be seen with a magnifying glass or microscope.

How do you get scabies?

Scabies mites are very sensitive to their environment. They can only live off of a host body for 24-36 hours under most conditions. Transmission of the mites involves close person-to-person contact of the skin-to-skin variety. It is hard, if not impossible, to catch scabies by shaking hands, hanging your coat next to someone who has it, or even sharing bedclothes that had mites in them the night before. Sexual physical contact, however, can transmit the disease. In fact, sexual contact is the most common form of transmission among sexually active young people. However, other forms of physical contact, such as mothers hugging their children, are sufficient to spread the mites. Over time, close friends and relatives can contract it this way, too. School settings typically do not provide the level of prolonged personal contact necessary for transmission of the mites.

Can you catch scabies from a dog or cat?

Dogs and cats are infected by different types of mites than those which infect humans. Animals are not a source of spread of human scabies. Scabies on dogs is called mange. When canine or feline mites land on human skin, they fail to thrive and produce only a mild itch that goes away on its own. This is unlike human scabies which gets worse and worse unless the condition is treated.