What is Scabies?
Scabies is a contagious, difficult to identify skin infestation, which is caused by tiny microscopic mites known as the ‘human itch mite’. Scabies mites take humans as their host and hence survive by burrowing under their skin. These mites usually transfer from skin to skin and even through infested clothing or bedding of the patient.
Scabies mites can survive on your skin for up to two months. Not only this, they reproduce on your skin surface; the female mites burrow into your skin and lay eggs. Eggs hatch into new mites, which then migrate to your skin’s surface. Infestation of other humans takes place when the infused female mite is transferred by touch or simply by brushing against the skin of an infected individual.
It takes about four to six weeks the symptoms to appear after a person is exposed to scabies. This is because the symptoms are mostly caused by an allergic reaction to the mites, their saliva, eggs, or waste products.
Scabies is not easily identified because some of its symptoms are similar to a few other skin ailments like psoriasis, acne, eczema, etc. Scabies symptoms include severe itching at night followed by red bruises or rashes over the affected area. Since scabies mites are most active at night, the most intense itching occurs at night. Continuous scratching at the infected site can create sores that become infected.
To diagnose scabies, your doctor examines your skin to look for signs of mites, which includes the characteristic burrows. There are various tests carried out to determine scabies. However, to perform any test, your doctor needs a skin scrap from the affected site on skin.
When your doctor locates a mite or burrow, they will take a scraping from that area of your skin to examine under a microscope. However, as scabies is spread very easily, it's often possible to make a confident diagnosis if more than one family member has the same symptoms.
Skin Scraping for Scabies
Skin scraping is commonly used to identify mites such as Sarcoptes. The skin scraping technique used can vary that depends on the type of ecto-parasite suspected. Have a look.
Collect skin scrapings as follows:
- Use a laboratory spatula or a No. 10 scalpel blade dulled by scraping the blade’s edge on a hard surface repeatedly.
- Place a drop of mineral oil on a sterile scalpel blade.
- Allow some of the oil to seep into the papule. Scrape six or seven times to remove the top of the papule. The tiny flecks of blood should be visible in the oil.
- Transfer the oil and scrapings onto a glass slide.
- Add 1-2 extra drops of mineral oil to the slide and mix well.
- Place a coverslip onto the slide and transport to the Microbiology Lab immediately.
A scraping test has several benefits:
- It facilitates the examination of both the full thickness of the epidermis and the contents of the skin hair follicles.
- Usually, several sites are sampled.
- It is a painless test; only a little skin agitation can be felt by the person.
- Effective way of sure identification.