Scabies is a contagious infection of the skin caused by a mite -- a type of parasite called Sarcoptes scabiei. Effective prescription-strength treatment is used for scabies infection. Scabies does not resolve without treatment and will progress in severity, causing a severe rash, often with superimposed bacterial infections while spreading to new areas of skin and transferring to other people as well.
Scabies produces itching and a pimple like rash caused by an immune reaction to the waste products produced by the mite. Over a few days or weeks, if left untreated, the infectious parasite will lay eggs and reproduce, causing further spread with new areas of itching and skin rash elsewhere on the body. Excessive scratching can cause open wounds or scabbing that can ultimately result in scarring of the affected areas. Seniors, disabled people and people with a weakened immune system will often experience less severe itching and rash but more crusting of the skin, where the mites and their eggs cluster in large numbers. This is known as crusted scabies.
A tendency to scratch the area of discomfort can lead to bacterial skin infection in addition to the initial mite infection. The bacterial infection, usually caused by staphylococci or streptococci bacteria that normally inhabit the skin, often arises in a wound created by scratching and can spread to other skin locations throughout the body, causing crusting, oozing, large open lesions, pus and fever. This is superimposed on the initial Sarcoptes scabiei infection and is often referred to as a super-infection. Bacterial infections require antibiotic treatment, which is a different treatment than the medication used to eliminate the scabies itself.
As the bacterial infection spreads, it can progress beyond a superficial skin infection, causing an infection of the blood called septicemia, which is extremely dangerous and difficult to treat once it reaches an advanced stage. The kidneys may also suffer as a consequence of the body's inflammatory response to streptococcal infection. This manifests as a failure of kidney function called post streptococcal glomerulonephritis, which develops due to inflammation of small blood vessels in the kidneys. Septicemia and post streptococcal glomerulonephritis can cause fevers, extreme fatigue, generalized pain, fluid retention, decreased urine output and even loss of consciousness. These symptoms require immediate medical attention because they can progress if not treated and can be fatal.
Spreading to Others
Untreated scabies can spread to other people. The most susceptible are family members and people who live in the same home or come into close bodily contact. The scabies mite can survive 48 to 72 hours outside the human body on furniture, towels, sheets and clothes. Most scabies is transferred by skin to skin contact, but crusted scabies is more contagious and can even spread through items that harbor the eggs or the mite itself. People do not become immune to scabies and will remain infected for long periods if they're untreated or become reinfected if the mite is not eradicated from the environment.