Scabies is a skin infection caused by the scabies mite, technically Sarcoptes scabiei, burrowing in the skin. A scabies infection is highly infectious even before any symptoms of the scabies rash are visible.
Scabies mites cause small, uneven tracks of small blisters accompanied by a severe itch due to allergic reactions to mites, eggs and their waste. Rashes may be located from the neck below, but typically on hands, wrists and elbows.
Scabies spreads from physical contact with another person carrying the eight-legged mites. Once infected, female mites burrow into skin and deposit eggs; within 21 days the eggs hatch and offspring move to the skin's surface.
A prescription is required to obtain a scabicide lotion, which treats scabies. The lotion kills scabies and eggs when applied from the neck down. The allergic rash may last up to a month after treatment.
To prevent reinfection, bedding and clothing need to be washed in hot water. Other items that may be infected should be sealed in plastic bags to prevent the mites from feeding.
A severe form of scabies called crusted, or Norwegian, scabies can infect suppressed immune systems. Crusted scabies cause a crusty rash of up to 2 million mites, compared to 15 mites in regular scabies.