Scabies is a very common skin infection that is caused by a mite that burrows under the top layer of skin and lays its eggs. The eggs hatch in a few days. The skin then becomes very itchy and a red, raised rash may appear. Itching is worse at night and can occur before the rash appears and can continue after the rash disappears. Sometimes the burrows can be seen; they appear as wavy brownish lines. The areas most affected are: between the fingers; between the toes; palms; heels; wrists and groin. Scabies is more common in children and young adults.
Scabies is highly contagious (easy to catch) and is spread via physical contact (person to person). It is more common in overcrowding situations. The sooner it is treated, the sooner the spread is stopped.
The presence of mites can be confirmed by taking a scraping from the burrows and examining it under a microscope. However, a negative scraping does not rule out the possibility of scabies.
An antiparasitic lotion is used to kill the mites and this should be applied over the whole body (excluding the face). A hydrocortisone cream can also be used to reduce the itching. It is important that all family members and close contacts also be treated at the same time as the initial patient. This helps prevent the spread.
refer : dermnetnz.org