Scabies and other mites causing skin disease

Description
This is an infectious disease of the skin caused by a mite. Scabies and other mites causing skin disease are diagnosed by examining a skin scraping under a microscope for mites or eggs. Scabies and other mites usually cause intense itching. Scabies is usually found between the fingers, on the front of the wrists, and in the folds of the elbows, wrists, armpits, buttocks and genitalia. Thread-like 'tunnels' (about 10 mm long) may be present in the skin, but these are often very difficult to identify. When mites have been transmitted from animals to humans, the mites are commonly found on contact areas, such as the arms, chest and neck. Scabies is usually transmitted by skin to skin contact. Very rarely, it is spread on underclothing or bed clothes that have been freshly contaminated by an infested person. The mites only live for a few days off the human or animal body. Although scabies mites from animals can live on humans, they do not reproduce in the skin. Some forms of skin disease in animals caused by mites (such as mange) can also be spread to humans. If an animal has mange, it is important to have a veterinarian diagnose which mite is causing the mange. Some mange mites on animals can spread to humans (for example, scabies and cheyletiella), while others do not spread to humans (for example, demodex). Sarcoptes (which causes scabies) can infect a wide variety of animals (including cats and dogs), while cheyletiella usually infects rabbits but can also infect cats and dogs.


Incubation Period
Itching begins 2-6 weeks after infestation in people not previously exposed to scabies and within 1-4 days in cases of re-infestation. Itching due to cheyletiella can develop within hours of handling the animal.


Infectious Period
Until the mites and eggs are destroyed by treatment.


Controlling the Spread of Infection
Exclude people with mites from the centre until the day after treatment begins. Inspect close contacts regularly for signs of infestation. Wash contaminated undergarments and other clothing worn by the child with hot water and detergent. Also wash bed linen and any other items the child has used in the past two days. Place all items which cannot be washed or dry cleaned in a plastic bag for four days to kill any mites or eggs. Bed mattresses and upholstered furniture can be vacuumed or gently ironed.


Treatment
Skin disease caused by mites can easily be confused with other skin diseases. Treatment should not begin until a doctor has confirmed the diagnosis following examination of a skin scraping for mites. This is particularly important for babies, pregnant women or people who already have other forms of skin disease. Treatment involves application of insecticidal cream, lotion or solution as prescribed by a doctor. If the mite has spread within the centre, all staff and children will need to be treated at the same time. Animals with skin disease caused by mites (mange) should be treated. A vet should examine a skin scraping to confirm the presence of mites and identify whether the mite can spread to humans. Animals and their bedding should then be treated with insecticidal washes, according to the vet's instructions.


Comments
Scabies is not an indication of poor cleanliness. A diagnosis of scabies should be considered in staff and children who have a long-standing itchy disorder. By the time it is diagnosed, many people may have been infested. All those who have had close skin-to-skin contact with the child (for example, family and close playmates) should be treated simultaneously. Otherwise treatment is likely to be unsuccessful.

Disclaimer
The information contained in this website is intended as a guide only. Wollongong Medical Centre is not liable for any problems that may arise from incorrectly or otherwise applying information found in this website.


Further General Information

The following web site has information on infectious diseases: www.health.nsw.gov.au/infect/ or contact the Division of Population and Planning on 4255-2200.

For information on a large range of medical conditions and problems visit www.mayoclinic.com