Scabies is a common skin condition characterized by an itchy rash, caused by an infestation of tiny mites. Many are unsure about how scabies is transmitted and whether it is a sexually transmitted infection (STI). This article clarifies these misconceptions, providing a clear understanding of scabies and its modes of transmission.
Is Scabies an STI?
Scabies is primarily transmitted through prolonged, direct skin-to-skin contact with an infested person. While sexual contact involves close skin-to-skin contact and can lead to transmission, it is not the exclusive or primary mode of spread for scabies. This contrasts with infections predominantly or solely transmitted through sexual fluids or specific sexual acts. Therefore, while scabies can be acquired during sexual activity, it is not classified as an STI in the same way as chlamydia or gonorrhea.
Transmission often occurs within households, among family members, or in crowded institutional settings like nursing homes, childcare facilities, or prisons where prolonged physical contact is common. The mite requires extended direct contact to transfer from one person to another. Casual contact, such as a quick handshake or hug, does not transmit scabies.
Understanding Scabies
Scabies is a skin infestation caused by the human itch mite, Sarcoptes scabiei var. hominis. These microscopic mites are barely visible to the naked eye, measuring about 0.2 to 0.45 millimeters. Once on the skin, the female mite burrows into the upper layer of the epidermis to live and lay her eggs.
A female mite lays eggs daily within the burrow. These eggs hatch into larvae within a few days. The larvae then migrate to the skin’s surface, developing into nymphs and eventually adult mites, completing their life cycle on the human host.
Recognizing Scabies Symptoms
The most characteristic symptom of scabies is intense itching, which often worsens at night. This severe itching is an allergic reaction to the mites, their eggs, and their waste products within the skin. A pimple-like rash typically accompanies the itching, appearing as tiny red bumps or blisters.
The rash and burrows commonly appear in specific areas of the body, including the webs of the fingers, wrists, elbows, armpits, waistline, buttocks, and genital area. In infants and young children, the head, neck, palms, and soles of the feet may also be affected. Small, raised, irregular tracks, called burrows, may be visible on the skin, created by the tunneling female mite. Symptoms may take two to six weeks to appear for a first infestation, or one to four days upon re-exposure.
Treatment and Prevention
Treating scabies requires a medical diagnosis and prescription medications. The most common treatment involves topical creams, such as 5% permethrin, applied to the entire body. In some cases, oral medications like ivermectin may be prescribed. A healthcare provider will determine the appropriate treatment regimen, and often two applications are needed, typically a week apart, to ensure all mites are eliminated.
To prevent re-infestation and further spread, all household members and close contacts of an infested person should be treated simultaneously, even if they do not yet show symptoms. Environmental decontamination is also important; all clothing, bedding, and towels used by the infested individual should be washed in hot water and dried on high heat. Items that cannot be washed can be sealed in plastic bags to allow any mites to die off. Avoiding prolonged skin-to-skin contact with infected individuals is also a preventive measure.