Scabies

Scabies is a common and very itchy skin condition caused by a tiny mite called Sarcoptes scabiei. It can affect people of any age but is most common in the young and the elderly. 

The mites that cause scabies are tiny parasites, smaller than a pinhead. They are usually spread by direct skin-to-skin contact with someone who already has scabies and sometimes, but rarely, from shared clothing, towels, or bedding.

A different type of mite causes scabies on pets and, therefore, cannot infect humans. People with scabies have an average of about a dozen adult mites on their skin; a few carry many more. Anyone can get scabies.

Rarely, a variant of scabies called crusted scabies (Norwegian scabies) can occur in patients who have a low immune system or who are elderly and ill due to other conditions. There are thousands of scabies mites on the skin in this variant, and it is highly contagious.

No, but it is common for several members of a family to have it at the same time as it easily spreads when people live together.

Itching is the main symptom of scabies, usually starting about a month after the mites are picked up. The itching can affect the whole body apart from the head and neck, although the elderly and infants may develop a rash on their head and neck.

The itch often gets worse at night. It is common for several people in the same family, and their friends, to become itchy at roughly the same time. 

The rash of scabies is a mixture of scratch marks and tiny red spots; scratched areas may develop crusty sores that can become infected and form into small pus spots. A widespread rash similar to eczema (dermatitis) is widespread.

The itchy rash can cover much of the body, but the mites are found mainly in the folds of skin between fingers and toes, the palms of the hands, the wrists, ankles, and soles of the feet, groins, and breasts. 

The scabies mites burrow into the skin in these areas to lay their eggs. The mites burrow into the skin leaving tiny spots and silver-colored lines on the skin.

Adult mites are tiny, only about 0.4 mm long, appearing through a magnifying lens or dermatoscope as one small dark dot lying at the end of a burrow.

Your doctor will usually diagnose scabies based on the family history and examination of the rash. To confirm the diagnosis, the doctor may wish to scrape off a small superficial section of the skin to be sent for examination under a microscope.

Yes, with the right treatment, it clears up quickly and completely; but if it is not treated, scabies lasts for months or even years. However, even after the mites are killed by treatment, the itching usually carries on for a few weeks before settling.

The treatment of scabies involves:

1. Using medication to get rid of your scabies.
2. Making sure that you, family members, friends, and any sexual contacts are all treated at the same time whether they are itchy or not. Several preparations are effective in the treatment of scabies.  

Follow the instructions issued with your treatment in detail; they will be based on the following principles:

• The mites may be anywhere, so the treatment must be applied to all areas of skin.  It should be below the neck in adults, all skin areas in children, including the scalp, not just to the itchy parts.
• The treatment should be left on for at least 12 hours before being washed off.
• When you wash your hands or any part of your body, you should reapply the treatment to the washed areas again.
• Two treatments, one week apart, are necessary to kill mites that have hatched out from eggs after the first application.
• One normal high-temperature wash of bedding and clothes should eradicate mites. Items that can’t be washed or dry cleaned can be sealed in a plastic bag for at least one week, or put in a freezer.

If you follow the instructions you are given, you should clear your scabies successfully. You must also make sure that all of your close contacts apply the treatment at the same time as you. Catching scabies again is, unfortunately, quite common.