1. Scabies Slideshow Pictures
2. Head Lice Slideshow Pictures
3. Ringworm Slideshow Pictures

Medical Author:

Mary Nettleman, MD, MS, MACP

Mary Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

View Full Profile

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

View Full Profile

Scabies is caused by an eight-legged mite (Sarcoptes scabiei var. hominis) that is less than 0.5 mm long. The life cycle of the scabies mite starts when the female tunnels (burrows) into the skin and deposits her eggs. Larvae hatch from the eggs within three to 10 days and molt to become nymphs. Nymphs mature into adults that deposit additional eggs and live approximately four weeks. Burrowing and movement of the mites cause intense itching due to a type of allergic reaction. If the person has never been exposed to scabies before, he or she may not show symptoms until four to six weeks after the initial infestation. Individuals who have been exposed in the past usually show symptoms within a few days.

Where does scabies come from? Scabies is almost always spread by protracted skin-to-skin contact with a person who carries the mite. The mites often begin to burrow at the site where they enter the body. Thus, skin transmission during sexual intercourse results in an infestation in the groin area.

It is important to point out that scabies is not always a sexually transmitted disease (STD) and may be acquired through casual contact. Less commonly, scabies infestation can happen through the sharing of clothes and bedding. Theoretically, you can get scabies from touching something that the mite is on, but that is not a major mode of transmission. The mite only lives for two to three days away from human skin. Scabies mites are not spread by contact with animals or pets.

Must Read Articles Related to Scabies

Allergic Reaction An allergic reaction is an overreaction to a harmless substance. Symptoms and signs of an allergic reaction include hives, rashes, swelling, itching, wheezing, ...learn more >>

Hives and Angioedema Hives is a sudden allergic skin reaction. Hives are raised reddish bumps that cause severe itching. Angioedema is similar to hives but the welts are larger and ...learn more >>

Rash A rash is a visible skin outbreak. Examples of noninfectious rashes include eczema, psoriasis, contact dermatitis, seborrheic dermatitis, rosacea, hives, and al...learn more >>

See the Entire Scabies Topic Guide »