Complications

Vigorous scratching can break your skin and allow a secondary bacterial infection, such as impetigo, to occur. Impetigo is a superficial infection of the skin that's caused most often by staph (staphylococci) bacteria or occasionally by strep (streptococci) bacteria.

A more severe form of scabies, called crusted scabies, may affect certain high-risk groups, including:

• People with chronic health conditions that weaken the immune system, such as HIV or chronic leukemia
• People who are very ill, such as people in hospitals or nursing facilities
• Older people in nursing homes

Crusted scabies, also called Norwegian scabies, tends to make skin crusty and scaly, and affects large areas of the body. It's very contagious and can be hard to treat.

Normally, someone with scabies has about 10 to 15 mites. In contrast, someone with crusted scabies may be infested with millions of mites.