Home > Scabies > Scabies Causes

Table of Contents

• Scabies Causes
• When Does Scabies Begin?
• Symptoms
• Pictures of Crusted Scabies
• Diagnosis
• Treatment
• Prevention and Control
• Free Brochure

"Overview: In most people, sustained skin to skin contact is one of the primary scabies causes. In the elderly or those with a compromised immune system, a type of scabies called crusted or Norwegian Scabies can result in the condition spreading due to brief skin to skin or skin to clothing/bedding contact. Scabies is more likely to spread where there is frequent skin to skin contact such as during sex, and in a setting where people live close together, such as childcare settings and nursing homes. The mites can only be seen with the aid of a microscope. Each mite can survive for 30 days on a human, where it will lay eggs under the skin, spreading the infestation. All individuals that have come in contact with the infested individual should be treated, including family members. It takes 2 weeks to 6 weeks for symptoms to appear. Mites that are not on a human host can only live for 3 days.  Itch and rash symptoms in most cases will last for up to 2 weeks but can last longer.

Treatment involves the use of a prescription scabicide to kill the mites with other products used to eliminate itch and to promote skin healing. If no progress is seen with over-the-counter products such as Midactin, be sure to see a Doctor for a prescription topical or oral medication that is formulated specifically to kill scabies and scabies eggs. Avoid scratching so that scabies is not spread to other areas of the body, and to keep bacteria from entering the skin and causing an infection. An infected person should not be touched for at least 8 hours after treatment. Human scabies mites are NOT spread by pets." 

Scabies Causes

Scabies causes can be linked to just one bug – the Sarcoptes scabiei mite. It tunnels into and under your skin, triggering uncontrollable itching. Anyone can get scabies and once one person in your house has them, they spread like wildfire, as they are highly contagious. These bugs are spread through close contact, such as sex, touching or coming in contact with mites that are on blankets or towels. It is not a sex-related disease. 

Scabies mites can survive at room temperature for 2 to 3 days on clothing, bed linen or other fabrics. Survival time depends on the humidity level in the room with longer survival associated with humidity over 30%.

When are People Infectious with Scabies?

People are infectious from the time they become infected until treatment are completed. Clothing and linen are infectious until 2 weeks after the last known exposure or until treatment is complete.

Scabies causes are also referred to as the seven-year itch mite, the human itch mite, and the scabies itch. The mites cannot be seen with the naked eye and have eight legs and a round body.

How Does Scabies Begin?

Once it has burrowed under your skin, it starts laying eggs. The eggs incubate for 3 to 10 days and then hatch into immature mites.

During this process, it is the secretions that leak out that cause the relentless itching. Most scabies infestations only start with about 10 mites. If not treated, the number of mites multiplies rapidly.

Symptoms

When Do Scabies Symptoms Begin?

Scabies symptoms begin in 4 to 6 weeks after being infested in people that have never been infested before. If you have been infested before, symptoms can appear in several days.

Because of the lag between infestation and symptoms, diagnosis can occur as long as 1 month after first being infested.

What are scabies symptoms?

The first symptoms are usually intense itching, followed by the scratching. Scratching can introduce infection-causing bacteria into the lesion.

On the skin look for zigzag blisters or S-shaped tracks on your body. The blister is where the female laid her eggs. Strange marks in odd areas like your armpits, the webs of your fingers or toes, under nails, around the waist, the inner elbow, nipples, penis, wrists, the groin area or buttocks? Red rash? This may be scabies.

Scabies tend to appear in areas where the skin is thin such as the elbows, wrists, web of the fingers, on the penis, shoulder blades and breast.

On children under 2 years, scabies rash can spread to the soles of the feet, palms, head, and neck.

Scabies rash may not be in the exact area where mites are burrowing.  Rash may not be as pronounced in the elderly.

Scabies also has an intense itch that worsens at night.

Diagnosis

There is no blood test for this disease. Your doctor will do one of several tests to confirm the presence of scabies:

• Skin Scraping: A test by swabbing a suspicious area that is inflamed and a skin scraping. He will be searching for the bugs themselves, their feces and eggs.  
• Burrow Ink Test: If the first skin scraping is not conclusive, the doctor may use a felt-tipped pen over the suspicious areas and then wipe it off. The ink will have leaked into the burrows. 
• Topical Tetracycline Solution: Solution is placed on skin area. Skin is then examined under a specialized light.
• Shave Biopsy: Skin layer is shaved at the site and examined under the microscope.
• Need Extraction: Needle is inserted into burrow location. The extract is examined under a microscope.

It is possible that a skin scraping will be negative even though a person is infected. The reason is the typical patient has less than 10 mites on their body, making it possible that the scraping will miss the infected area.

If you have crusted scabies (caused by the Norwegian mite), a person can have thousands of mites under the skin and is very infectious.

Differential Diagnosis

Scabies may be confused with body lice, bed bugs, chiggers, shingles, impetigo, ringworm, eczema or hives.  Scabies is not spread by pets such as dogs or cats.  Dog scabies is spread by another type of mite which causes mange.

Scabies can also be confused with other conditions that cause skin bumps, rash, and itch.

• Acute urticaria: usually papules and itching all over body
• Eczema: generic term for an inflamed skin condition
• Atopic dermatitis, which also causes small skin bumps due to hypersensitivity
• dermatitis herpetiformis
• Impetigo: causes tiny blisters
• Folliculitis: hair follicle inflammation
• Insect bites
• Pyoderma: skin infection
• Psoriasis: dry, cracked, itchy and possibly skin blistering
• Syphilis: red/brown spots or rash
• Mycosis fungoides: T-cell lymphoma that impacts the skin
• Lupus: purple or red skin lesions
• Tinea: ringworm and other fungal infections

Treatment

Options Without a Prescription

More often than not, you will need a prescription to combat scabies, but there are over-the-counter scabies remedies to try for those that want to avoid insecticide based prescription products such as those available from Midactin.  Let your doctor know if you choose to use over-the-counter medications so that he can monitor your progress.

You should also know that the itching and rash may last for up to two weeks, even after treatment and you may need to repeat the course of medication. Itching can be helped by a Sulfur based soap such as Naturasil Sulfur and Lavender Soap. It also includes soothing ingredients such as Palm Kernel and Coconut Oil. Each ingredient has been selected based on their anti-parasitic properties.  This approach has been used for centuries and can be used along with other natural and prescription treatment methods.  

Scabies skin itch can also be addressed with over the counter antihistamines such as Zyrtec or Benadryl.

Prescription Scabies Treatments

Here are some of the treatment approaches that will be used by your doctor:

• 5% permethrin cream: Permethrin is a common insecticide used in a topical ointment at a concentration that will kill scabies mites. It is prescribed for individuals 2 years of age or older and is the treatment methods of choice. The product is applied from head to toe before going to bed. Leave on for 10 to 14 hours and wash off.  Follow directions provided by your Doctor.  Cases of Norwegian scabies (crusted scabies) requires 2 applications each week.
  
  
• 10% Cromiton Lotion (infrequently prescribed due to treatment failure related resistance issues): This product (called Crotan or Eurax) is also approved by the FDA. It is not approved for children. In general, the product is not considered to be as reliable as Permetrhin.
  
  
• 1% Lindane Lotion (use with caution, may cause nervous system toxicity if used incorrectly): Lindane lotion is used after other products have failed to cure the scabies. The product is toxic when swallowed carries warnings that it should not be used with premature infants, pregnant women, breastfeeding women, those with skin sores and more.  Carefully follow your Doctor's instructions.
  
  
• Invermectin (Stromectol): Invermectin for scabies causes is taken orally and is used particularly when an individual is suffering from crusted scabies. It is not used until other treatment methods have failed. It is taken with water on an empty stomach for 2 doses over 7 days. It is not used on children that weight less than 15 Kg or in pregnant women.  Follow your Doctors directions.
  
  
• Sulfur Ointment: Infrequently prescribed due to messy application and odor.  Safe for infants younger than 2 months, lactating or pregnant women.

• If the skin becomes infected, a Doctor will prescribe antibiotics in a topical or oral form. 

How Long Does Scabies Treatment Take?

Symptoms should start to subside after the first treatment. Itching can continue for 2 to 3 weeks.

Scabies Prevention and Control

Although scabies mites can only live off of a human for 3 days, it is smart to clean all linen and clothes used by the infested person.  Wash in hot water followed by 20 to 30 minutes in the dryer. Clothes and linen can also be dry cleaned or sealed in plastic for 3 days.

 Be sure to vacuum all rooms and also clean all nearby items with a miticide (also called scabicide - scabies mite killer) such as Benzarid for scabies or by spreading a natural dust product such as Fossil Shell Dust (applied in a thin layer to cracks, under furniture to kill mites naturally). If you have carpet, add some miticide to the carpet cleaner (test to make sure that products used will not harm carpet color).

It is not necessary to apply a pesticide to avoid scabies.

Brochure

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