Scabies

What is scabies?

Scabies is a highly contagious skin rash that occurs when mites called Sarcoptes scabiei burrow in the skin through tunnels. The often intensely itchy rash results from the skin’s reaction to the mites that live within the top layer of skin. The rash spreads easily through skin-to-skin contact, making the rash spread rapidly in settings like schools, nursing homes, and childcare facilities. Once diagnosed, typically the person with the rash as well as those they live with should get treated, given the contagious nature of the mites. 

Anyone can have scabies, and there are nearly 200 million cases of scabies across the world. Scabies is easy to diagnose and treat, but the symptoms of scabies can linger for many weeks after treatment. The rash of tiny, raised bumps can show up differently depending on the person’s skin tone. Once you see a doctor for a potential scabies diagnosis, you can quickly treat the rash with effective topical medications.

 

What causes scabies?

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Scabies is caused by an infestation of the Sarcoptes scabiei mite, also called the skin itch mite. When the female mites burrow, they create tunnels just under the surface of the skin to lay eggs. The mites remain under the skin where the new mites grow and come to the surface where they continue to spread. Mite eggs take 3 to 4 days to hatch, and once hatched, they mature in 10 to 15 days before starting the mating and hatching process over. 

The characteristic rash of rabies occurs as the skin’s reaction to the mites. There are a few main ways that people get exposed to the contagious rash and scabies that burrow. The most common way is through direct and prolonged skin-to-skin contact with someone who already has scabies. As the skin makes contact, the mites can transfer to a new host and continue the burrowing process. People can also contract scabies through contact with fabrics or furniture on which mites are present. In other cases, people can be in environments where mites are present and become infested by direct contact with the mites.

What are symptoms of scabies?

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Symptoms of scabies can take anywhere from 2 to 5 weeks to appear after the mites burrow. This timeframe decreases for those who have had scabies before to 2 to 4 days. The main symptom of scabies is a rash on the skin that starts slowly and spreads over time. 

Other common signs of scabies include the following:

  • Severe itchiness that often gets worse at night
  • Bumps or uneven skin that resemble hives, bites, or pimples
  • Sores that form as a result of itching the rash bumps
  • Skin-colored or grayish-white wavy lines visible on the skin that result from the burrow lines of the mites

Scabies can appear on many parts of the body at the same time. The mites most typically burrow in areas with skin folds. Mainly, scabies is found:

  • On the chest
  • In between fingers and toes
  • Under the armpits
  • On the inner elbows and insides of wrists
  • In the groin and genital area 
  • Near the waist and belly button 

Scabies is still contagious even before symptoms develop, making the spread of the rash more likely if you are unaware you or someone you regularly contact have the skin condition.

Are there any risk factors or groups for scabies?

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Anyone is susceptible to scabies, as scabies is not a genetic condition or one preventable with good hygiene habits. However, there are some groups of people that are more likely to develop scabies. Since scabies can spread rapidly through any amount of close physical contact, there are many environmental factors that could make someone more vulnerable to scabies.

Common risk factors include:

  • Living in crowded conditions with close proximity to others, including sharing of many household items like towels, blankets, sheets, and furniture
  • Residing in a nursing home or rehabilitation facility with regular contact with other residents and staff
  • Children and infants who maintain a lot of physical contact with their family and classmates 
  • Being a healthcare worker in close contact with patients who may have scabies
  • Frequently visiting or attending places where scabies can spread fast, like schools, daycares, and locker rooms
  • Making contact with someone known to have scabies, such as friends, family, or sexual partners

How is scabies diagnosed?

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Your primary care physician can typically diagnose scabies by a simple examination of the impacted skin. Your doctor will look for symptoms of scabies, mainly the itchy rash. If the rash is present, but your doctor wants to confirm the presence of the scabies mites, your doctor may apply mineral oil to the skin to painlessly collect a sample of skin to view under the microscope. Scabies mites are a whitish color and are as small as the tip of the needle, so you need a microscope to see the mite clearly and identify the presence of mites like eggs or feces. 

A scabies diagnosis becomes further confirmed by asking if anyone else in your household or if someone in your child’s school class has been infested or is experiencing a similar rash. Since the rash can appear over time, you should monitor symptoms because a diagnosis for scabies may produce negative results early on but then becomes clear over time that an infestation has started. 

How is scabies treated?

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There are effective treatments for scabies that aim to kill the mites and burrowed eggs. All of the main treatments for scabies require a prescription from your doctor since the ingredients are not available over-the-counter nor are home remedies effective at killing the mites and stopping infestation. Medicine to treat the rash and kill the mites takes the form of a cream, lotion, or pill. 

Since scabies can spread so easily to other parts of your body and easily to others, most treatments are designed to cover your whole body to make sure you are entirely rid of scabies. Following your doctor’s instructions for treatment is essential in controlling the condition. Given the susceptibility of those in close proximity to someone with scabies to become infested, the treatment for scabies is generally prescribed not only for the affected individual but also for their family, friends, or whoever they are in close proximity with on a regular basis.  

The most common scabies treatments include the following:

  1. 5% permethrin cream: Permethrin cream kills mites and eggs. Typically, your doctor will advise you to apply the cream on your entire body from the neck down for a set course of days. 
  2. 10% sulfur ointment: Sulfur ointment applies overnight and gets rinsed off in the morning for a course of 5 days. 
  3. Ivermectin: This treatment is an oral medication, which is often an option for immunocompromised people or for people who have not responded well to topical treatments. There are risks for this option for people who are pregnant or people who weigh less than 35 pounds. 

There are other treatments available for the persistent rash symptoms, such as antihistamines or itch relief lotions.

Should you see a doctor for scabies?

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You should see a doctor as soon as you suspect you have scabies or start noticing symptoms of scabies. Prompt treatment is essential to stopping the spread of the conditions and thoroughly treating the individual to remove the mites and the eggs. You should also communicate with your doctor if you notice symptoms of scabies returning or if you have an adverse reaction to your prescribed medication. 

Skin conditions often share symptoms, so even if you think a rash is a result of a different condition, you should still visit your doctor to confirm a diagnosis. In its early stages, scabies is typically not threatening or damaging to the body. However, left untreated, scabies can lead to infection, which can have serious complications, especially for vulnerable groups of people like children or immunocompromised people.

What is the outlook for people living with scabies?

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The outlook for scabies is generally positive because treatment can kill the mites to stop the infestation. People can get scabies multiple times, but preventative measures can help keep scabies mites from coming back. 

After a scabies infestation, you can wash all your clothes and other fabric items, like sheets, towels, and blankets, to sanitize the materials. Anything you cannot wash you should try to bag for a few days or move to an isolated area to starve the mites of food. Keeping your living space clean and dusted regularly will help prevent a scabies mite infestation.

What are the complications of scabies?

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Possible complications of scabies are a repeated infestation or a more serious form of scabies, called crusted scabies. Crusted scabies form patches of scaly and crusty skin. People with this kind of scabies can have a harder time treating the infestation, making the uncomfortable symptoms last longer. In addition, the infestation is much more significant in terms of the quantity of mites than a regular case of scabies. People who develop crusted scabies should talk with their doctor about the best treatment options and good preventative measures to avoid infection or other skin complications.

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