Human scabies is a contagious parasitic infestation, which is caused by Sarcoptes scabiei var hominis. This is a microscopic mite that’s not visible to the naked eye. It burrows into epidermis layer of the skin to lay eggs. This further triggers a host immune response leading to extreme itching caused in response to these itch mites. Due to intense itching, the host may develop sores on the skin. If left untreated, it can even cause some serious problems like septicemia, chronic kidney disease, and heart disease.
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Scabies is one of the most common skin conditions that affect more than 130 million people globally at any time. It can affect people of any age, race or religion. So, it doesn’t matter how clean you stay, you can still get affected by coming in close contact with an infected person. Scabies is more vulnerable in young children, and elderly when they live in shared community spaces like child care, playschools, nursing homes, etc. This is because such crowded public spaces are at most risk of spreading scabies, as you never know who around you may be infected with this skin condition.
Scabies mites burrow on the skin surface where adult female mites lay eggs. Eggs hatch after 4-6 weeks and the then infested person begins to develop an allergic skin reaction to the presence of mite proteins and feces, and this causes extreme itching. Scratching your skin to relieve itching can further lead your skin exposed to other secondary infections like eczema, psoriasis, skin sores, etc. Scabies-associated skin infection is more common in tropical regions, especially in people with immune-mediated complications like acute post-streptococcal glomerulonephritis (kidney disease) as well as rheumatic heart disease. Evidence of renal damage has also been found in 10% children infected with scabies due to poor living conditions. If the skin condition is not treated for a long period of time it can even contribute to permanent kidney failure.
Diagnosis of scabies is done by looking for characteristics like extremely itchy skin with an appearance of linear burrow around the wrists, finger webs, soles of the feet, and ankles. Prolonged itching in a patient may even lead to the development of scabies nodules found in genital areas like scrotum, penis, as well as breasts of a female. To look for the presence of scabies mites in the skin, the scarp of your skin is taken by a doctor with the help of a sharp blade. This skin scrape is observed under a microscope to see the presence of parasitic mites.
Treatment and Control
Primary treated of affected individuals is preferred by prescribing them a topical scabicide agent like permethrin 5% (but it’s not recommended for infants under 6 months), 5% malathion lotion, 10–25% benzyl benzoate emulsion, or 5–10% sulfur ointment. All these topical creams/lotions/ointments are needed to be applied all over the body and left overnight to kill the mites. In addition, oral ivermectin (but not for pregnant women and underweight individuals) is given to patients with crusted scabies. Your entire family members and close friends must be treated at the same time.
Secondary management involves treatment of the complications associated with scabies, like impetigo, using prescribed antibiotics or antiseptics.
Control: Scabies population control is identified by some countries as a public health priority, as it is a major concern and can easily spread to people in close contact with the patient. One important aspect of controlling and eliminating scabies is by organizing programs to make people aware of existing clinical and public health systems.