People with scabies experience itching that usually worsens at night and blisters or bumps on their skin that form into burrows, reports Mayo Clinic. While almost any part of the body can be affected by scabies, it usually occurs in adults and older children between fingers, in armpits, on the inner elbow, around breasts and around the male genital area. The scalp, face, neck, palms and soles of the feet are common places for scabies to appear in younger children.
An eight-legged mite called Sarcoptes scabiei causes scabies when it burrows under the skin and creates a tunnel to lay eggs, explains Mayo Clinic. When the eggs hatch, the larvae move to the surface of the skin and people suffer from an allergic reaction. Scabies is highly contagious, and while people who have never had scabies before may not exhibit symptoms for up to six weeks, they can still spread the condition. People who have suffered from scabies in the past may experience symptoms within a few days of exposure to the mites.
The scratching caused by scabies can lead to the development of bacterial infections such as impetigo, according to Mayo Clinic. People with weakened immune systems due to HIV or chronic leukemia, people who very ill and older people in nursing homes are at risk of developing crusted scabies, a more severe form of the condition that is highly contagious and difficult to treat. Crusted scabies, also known as Norwegian scabies, may cover large parts of the body and appear scaly and crusty.