Scabies, also known as the seven-year itch, is caused by a parasite that buries itself in your skin

Photo Credits: Daily Mail UK, WHO

Name
Scabies aka the seven-year itch (this nickname comes from the fact that it can be hard to get rid of)

Transmission

• An infestation of the skin by itch mites (microscopic bugs)
  • The mites live in the environment and have been infecting humans for thousands of years
  • The mites burrow into the upper layer of the skin where they live and lay eggs
• Person to person transmission is common with skin-to-skin and sexual contact
  • Scabies spreads very quickly in crowded places or places with frequent body contact (schools, prisons, hospitals, and elderly homes are often sites of outbreaks)
• Crusted scabies is a more severe form which occurs in people with poor immune systems (elderly, disabled, etc)
  • These people have thick crusts of skin that contain large numbers of mites and eggs, so they are very contagious and can spread the infestation easily from person to person

Geography
Worldwide

Incubation Period
4 – 6 weeks after exposure but only 1 – 4 days for people who have had scabies before

Signs and Symptoms

Even before symptoms show, people can spread mites to others. Common symptoms include:

• Intense itchy rash especially at night (mostly on the wrist, elbow, armpit, webbing between the fingers, nipple, penis, waist, belt-line, and buttocks)
• Skin blisters
• Skin scales
• Skin sores
• Tiny raised and crooked lines on the skin surface (burrow lines from the mites)

Diagnosis
Clinical diagnosis is based on the appearance and distribution of the the rash and the presence of burrows, however a confirmatory diagnosis requires identifying the mites, eggs, or fecal matter of the mites by obtaining a skin scraping and examining it under a microscope

Treatment

• Treatment is with scabicides (cream and lotion products that kill the mites and their eggs)
• In addition to treating the skin, it is important to wear clean clothing after each treatment
• It is also important for those around the infected person to get treated at the same time to prevent reinfestation

Prognosis

• Although mites can live in the skin for 1 -2 months, scabies is curable
• If itching continues more than 2-4 weeks after initial treatment or if new burrows or rashes continue to appear, it may be necessary to repeat the treatment

Prevention: What Can You Do?

• Avoid direct skin-to-skin contact with an infested person
• Avoid contact with their clothing or bedding

Sources:
https://www.cdc.gov/parasites/scabies/
http://www.who.int/lymphatic_filariasis/epidemiology/scabies/en/