Information About Scabies
Scabies is a skin condition caused by the human itch mite (latin name Sarcoptes scabiei). (1) The human itch mite is a small 8-legged insect that cannot be seen with the naked eye. Scabies develops when the mite burrows into the skin and causes an inflammatory reaction. The inflammatory reaction is extremely itchy. The immune system responds to the mites, eggs, and mite feces with an allergic reaction.
If you’ve ever suffered from scabies, you know how hard it can be to resist the urge to scratch. Unlike with mosquitoes, insect repellents cannot be used to repel scabies.
The mites that cause scabies like to burrow into human skin in order to live and feed. Humans are their only host. The scabies mite can only survive 48-72 hours outside of a human host.
Scabies is Common
First of all, outside of the United States, scabies is incredibly common. There are millions of cases every year. Travel to another country is a risk factor for developing scabies. Within the U.S, scabies is more common in children and among persons living in together in large groups such as the elderly.
How do you get scabies?
Scabies is transmitted from person to person. If someone at home has scabies, chances are that everyone in that house has scabies. Scabies is usually transmitted by skin to skin contact. However, it can also be transmitted from furniture, bedding, clothing, and any linen. Scabies cannot be transmitted by short human contacts such as from a handshake or hug.
Pets infected with other mites cannot transmit scabies.
Scabies Can Be Asymptomatic At First
Signs and symptoms of scabies can take weeks to develop in first time cases. There can be a latency period of 2-6 weeks from the time of infection to the time symptoms develop. For people who have had scabies before, the skin can react more quickly within 1-4 days. As a result, asymptomatic people who are infected with scabies without knowing it can transmit the infection to people around them.
Classic Symptoms of Scabies
• Itching at night that keeps the person awake
• Scabies rash — The rash can resemble small bumps distributed in a line under the skin.
• Sores from scratching and secondary skin infections
• Thick Crusts
Classic Distribution of Scabies Rash
The scabies mite prefers to burrow in certain parts of the human body. They love:
• The skin between the fingers and around the nails
• Elbows and wrists
• Skin around the nipple
How to Diagnose Scabies
A dermatologist can diagnose scabies from the classic distribution of the rash or by directly visualizing the mite under the microscope. The mite can be seen microscopically in a skin scraping sample. A skin scraping is a painless procedure where the dermatologist scrapes off pieces of dead skin from the area of the scabies rash. In the most common form of scabies infection, a person will be infected with 15-20 mites on their skin.
The diagnostic challenge lies in scraping a piece of skin that has the scabies mite in it. The dermatologist can diagnose scabies based on the classic presentation even if he or she is not able to visualize the mites or eggs.
How to Treat Scabies
Luckily, scabies is easy to treat. Hence, the itching will go away very quickly. There are no over the counter treatments for scabies. Thus, a prescription medication is necessary to treat scabies. The medication is usually applied at night to the entire body and washed off in the morning.
Medications that Kill the Scabies Mite
• Permethrin Cream
• Lindane lotion
• Oral ivermectin
Alternative Treatments and Home Remedies for Scabies
Scabies treatments are of low toxicity. However, many people are worried about covering their bodies and the bodies of their children with one of these chemicals. They may resort to finding home remedies to treat scabies.
In addition, the most effective home remedy for scabies is tea tree oil. (2) But this treatment has no evidence in humans. Tea tree oil is available online and in health food stores. It has been shown to have insecticidal activity against the scabies mite within in vitro studies. However, none of these studies have been conducted in humans.
Who should be treated for scabies?
Scabies is very contagious. Therefore, the person suffering from scabies and any close contacts or sexual partners must be treated. Treatment is necessary even if the close contacts do not have any symptoms. This prevents new outbreaks of scabies reinfection from occurring.
Treating the Symptoms of Scabies
Like I mentioned earlier, scabies is very itchy. As a result, antihistamines, topical steroids, and pramoxine lotion can be used to control the itch.
Secondary skin infections can occur as a result of scratching and bacterial entry through traumatized skin. Antibiotics treat these skin infections.
Treating Infected Bedding and Clothing
Scabies must be eradicated both in the home and in human hosts. All clothing, towels, and bedding should be washed in hot soapy water. (2) The linens should then be dried on the highest heat setting. If an item is not machine washable, it should be put in a sealed plastic bag for 2-4 weeks. The mites will die if there is no human host available.
Conclusion on Scabies
In conclusion, scabies is a common skin condition that is spread by infection with the human itch mite. Scabies is transmitted person to person from skin to skin contact. The most common symptom is extreme itching and topical prescription treatment usually does the trick to get rid of this infection. Lastly, see your dermatologist if you think you may have scabies or need more information about scabies.
- American Academy of Dermatology. Scabies Overview. https://www.aad.org/public/diseases/contagious-skin-diseases/scabies#overview
- The Dermatologist. What to do about Scabies. http://www.the-dermatologist.com/content/what-do-about-scabies