Scabies

What is Scabies?

Scabies is a skin condition that can spread easily from person to person. It’s caused by a tiny mite called Sarcoptes scabiei which digs under the skin and causes intense itching. This itching can be very bad, especially during the night.

Scabies can be caught by touching someone who already has it. This is why it often spreads among family members and other people who are in close contact. In 2009, the World Health Organization labeled Scabies as a neglected disease, meaning that it’s a serious health issue, especially in less developed countries.

If someone has scabies, it’s important to identify it quickly and start treatment right away. Otherwise, if it’s not correctly diagnosed, it can lead to an outbreak, cause other health problems, and increase healthcare costs.

What Causes Scabies?

The tiny bug or mite that causes scabies is called Sarcoptes scabiei var. Hominis. This mite is a kind of arthropod, or an invertebrate animal with an exoskeleton, segmented body, and jointed limbs, and it is part of the same class as spiders.

Scabies can appear in three forms: classic scabies, nodular scabies, or a highly contagious form known as Norwegian scabies.

The Sarcoptes scabiei mite lives in the outer layers of human skin, but it can also live on animals. Scabies is a common skin condition that can affect people everywhere. The female mite starts a scabies infection by digging into the top layer of the skin and laying her eggs. These eggs then grow into larvae, nymphs, and finally adults.

In the classic form of scabies, a person might have between 10 to 15 mites. For a person to catch scabies from someone else, skin-to-skin contact usually needs to last for about ten minutes. However, scabies can also spread through shared clothing or bed sheets. Typical symptoms of classic scabies include thick, rough patches of skin, often occurring on the palms of the hands, soles of the feet, or under the fingernails.

The nodular form of scabies is another version of the classic form. This kind of scabies causes red, itchy bumps, especially near the armpit and groin areas. These bumps are thought to be an allergic reaction to the female mite.

Norwegian scabies, or the crusted variant, can result in millions of mites living on a single person. This form of scabies tends to affect people with a weak immune system, such as individuals undergoing immunosuppressive therapy, people with diabetes, those with HIV, or older people. Even brief contact with a person suffering from Norwegian scabies, or with materials they have touched, can lead to infection. The severity of this form of scabies depends on the person’s immune health and the number of mites they have.

Risk Factors and Frequency for Scabies

Scabies is a skin condition that affects millions of people worldwide every year – an estimated 300 million to be precise! It’s such a significant health problem that the World Health Organization identified it as a neglected skin disease in 2009.

This condition is particularly widespread in certain geographic regions – Africa, South America, Australia, and Southeast Asia. Factors such as poverty, malnutrition, homelessness, and poor hygiene practices contribute to its prevalence in these regions.

Scabies most commonly affects children and young adults. Complications and secondary infections resulting from scabies can lead to severe health problems. These complications can include abscesses (pockets of infection), swollen lymph nodes, and a serious kidney disease called post-streptococcal glomerulonephritis.

• Scabies affects an estimated 300 million people worldwide each year.
• It is most common in Africa, South America, Australia, and Southeast Asia.
• Poverty, poor nutrition, homelessness, and inadequate hygiene contribute to its high prevalence.
• Scabies is most common in children and young adults.
• It can lead to severe health issues such as abscesses, swollen lymph nodes, and a kidney disease called post-streptococcal glomerulonephritis.

Scabies can also cause outbreaks in schools, nursing homes, hospitals, prisons, and other places where people live in close quarters in industrialized countries. These outbreaks can happen sporadically or within institutions and areas of overcrowding.

Signs and Symptoms of Scabies

Scabies is a skin infestation characterized by small white lines on the skin, indicating the hatching of mites beneath your skin. This condition could lead to uncomfortable itching, red skin bumps, and skin hardening due to continuous scratching. These signs appear in common areas such as:

• Folds of your skin
• Armpits
• Belly Button
• Spaces between your fingers
• The beltline
• Nipples
• Buttocks
• Areolae of female breasts
• The inner parts of wrists
• Male genitalia

Often, scabies leads to secondary bacterial infections. An example is impetigo, a condition facilitated by the mites burrowing under your skin which creates an environment for bacteria like Streptococcus pyogenes to thrive and avoid the immune system.

It’s essential to remember that scabies does not always present with its usual symptoms. Monitoring within a family or group of people living or working closely together is necessary. For instance, if multiple members experience itching, it might be a sign of a group scabies infestation.

Testing for Scabies

Scabies is typically diagnosed by looking at the skin rash and considering the patient’s medical history. This skin condition can also be identified by examining skin scrapings under a microscope. This traditional method, however, often fails to correctly identify scabies due to the potential of issue in the skin sample collected.

Some alternative techniques, like videodermatoscopy, are also used during the physical exams. This technique uses a video camera attached to digital systems that has optic fibers and high magnification lenses. Unfortunately, many U.S. offices don’t have this technology. Videodermatoscopy is noninvasive (or in other words, it doesn’t break the skin or physically enter the body) and gives a detailed view of the skin up to the superficial layers, identifying scabies mites, burrows, and even eggs. It’s useful for following up with patients after treatment, identifying any surviving mites in the case of persistent infection or unsuccessful treatment. Despite these advantages, it is not commonly used in day-to-day medical practice.

Dermoscopy, another technique similar to videodermatoscopy, is becoming more popular. It is handheld and does not require a computer connection. The device has a lens that magnifies up to 10 times, which allows doctors to spot the characteristic burrow structures of scabies, often referred to as the “jetliner trail.” However, it may not clearly show these burrows on dark skin or in hair-covered areas.

In cases where the diagnosis is still unclear, a skin biopsy (where a small sample of skin is taken for examination) can confirm the presence of scabies. A newly developed blood test can also assist with the diagnosis, but it is not commonly used in the United States.

Treatment Options for Scabies

Scabies, a skin condition caused by tiny mites, can be treated in a variety of ways. Research suggests that when used properly, many of these treatments are equally effective. They include a cream called permethrin, a lotion called crotamiton, and a medication taken by mouth known as ivermectin. Side effects from these treatments are not common.

Permethrin cream is commonly used to treat scabies. The cream is usually applied once a week for two weeks. Some challenges with this treatment can include potential resistance from scabies to the cream, patients not following treatment instructions, and rare allergic reactions.

Another way to treat scabies is with ivermectin, which is taken orally. Despite not being officially approved for scabies treatment by the U.S. Food and Drug Administration, it is sometimes given to individuals aged ten and above. Two doses of ivermectin help to kill the scabies mites. This method is preferred because it’s easy to use, the side effects are generally favorable, and it’s safe. Patients are often more likely to follow the treatment instructions with oral ivermectin compared to permethrin cream. The risk of misuse is decreased due to the tablet form. Notably, ivermectin tablets have shown to be more efficient than permethrin cream in managing scabies outbreaks. This is particularly important when treating scabies in people living close together, such as in homeless shelters, prisons, and healthcare facilities.

Other potential treatments for scabies include lindane lotion, sulfur preparations, malathion lotion, and ivermectin cream.

However, it’s worth noting that treatment options can be limited for people with a resistance to certain treatments, or those who can’t use certain treatments due to cost, availability, or potential toxicity. This can be especially true for pregnant women and children.

Treatment for scabies often fails or needs to be repeated, and it’s important to find the cause to prevent further infections and community outbreaks. Common reasons for treatment failure could be lack of treatment for people who have close contact with the infected person, not properly cleaning beddings and clothes at the time of treatment, and not following treatment instructions. For severe cases of scabies, where mites may develop resistance to ivermectin, another medication called moxidectin is recommended.

What else can Scabies be?

Scabies, a condition caused by microscopic mites, can often look like other skin problems. It’s not uncommon for people to initially mistake it for:

• Infections caused by bacteria, fungi, parasites, or viruses
• Eczema
• Skin inflammation (dermatitis prurigo nodularis)
• Lupus erythematosus, a chronic autoimmune disease

Because of these similarities, it’s possible to misdiagnose scabies as one of these other conditions.

What to expect with Scabies

If the patient, along with their close contacts and family members, is treated, the chances of successful recovery are high. Given the right treatment, patients are usually able to fully recover. However, without treatment, the infection can spread to other people in the community, leading to a potential outbreak amongst the populace.

Possible Complications When Diagnosed with Scabies

Scabies can lead to a number of issues such as never-ending itching, trouble with sleeping, additional bacterial infections and even spreading the disease to others in the community.

Potential Issues:

• Persistent itching
• Difficulty in sleeping (Insomnia)
• Secondary bacterial infections
• Outbreak of disease to the community

Preventing Scabies

Scabies is a condition that can easily spread from one person to another through regular skin contact or by sharing clothing or bed sheets. Scabies is treated by quickly addressing the infection in the individual and their close contacts, as well as by cleaning items they have been in touch with, like bedding, towels, and clothes.

It’s especially important to keep infected persons separated from others in crowded places like hospitals to prevent the infection from spreading. All the personal items used by the person with scabies, like their bedding, towels, and clothes, should be thoroughly cleaned. This includes machine washing these items in hot water (at least 75 degrees Celcius) and drying them with hot air.

In some cases, the doctor might also give a skin cream or lotion to the close contacts of the infected person. This is done as a preventative measure to stop them from getting scabies too.