Scabies also known colloquially as the seven-year itch, is a contagious skin infection caused by the mite Sarcoptes scabiei. Classified by WHO as water related disease, most often transmitted by direct skin-to- skin contact.with higher risk with prolonged contact. May be transmitted from objects such as clothing, bedding, furniture, or surfaces with which a person infected with scabies might have come in contact. The mite is a tiny, and usually not directly visible, parasite which burrows under the host's skin, which in most people causes an intense itching sensation caused by an allergic response. Initial infections require four to six weeks to become symptomatic. Reinfection, however, may manifest symptoms within as few as 24 hours. Scabies mites can survive without a human host for 24 to 36 hours .Crusted scabies, formerly known as Norwegian scabies, is a more severe form of the infection often associated with immunosuppression.

Mass treatment programs that use topical permethrin or oral ivermectin have been effective in reducing the prevalence of scabies in a number of populations. The simultaneous treatment of all close contacts is recommended, even if they show no symptoms of infection, to reduce rates of recurrence.

Ivermectin is an oral medication shown by many clinical studies to be effective in eradicating scabies, often in a single dose.