Scabies – Symptoms and Causes
Overview
Scabies is a contagious skin condition caused by tiny mites called Sarcoptes scabiei. These mites burrow under the skin and cause intense itching, and it gets worse at night.
This condition spreads quickly through direct physical contact. People in close living situations like families, schools, daycare centers, nursing homes, and prisons face a higher risk of outbreaks.
Common symptoms include:
- Severe itching, especially at night
- Rash with small bumps
- Visible burrow lines on skin
Treatment typically involves prescription medications that kill both the mites and their eggs. These come as creams applied to the skin or pills taken by mouth.
Even after successful treatment, itching may continue for several weeks as the body’s allergic reaction gradually subsides.
Healthcare providers often recommend treating all household members or close contacts to prevent reinfection.
Signs and Symptoms
Scabies typically causes intense itching that often gets worse at night. You may also notice thin, wavy lines on your skin made up of tiny blisters or bumps.
These are tunnels created by the mites as they burrow under your skin. The symptoms commonly appear in skin folds and can affect many body parts.
In adults and older children, watch for signs in these areas:
- Between fingers and toes
- Inside wrists and inner elbows
- Armpits
- Around the waist
- On the chest and near the nipples
- Around the belly button
- In the genital area, groin, and buttocks
- On the soles of feet
For infants and young children, scabies often appears in different locations:
- Fingers
- Face, scalp, and neck
- Palms of hands
- Soles of feet
It’s important to note that if you’ve had scabies before, symptoms might start within days of exposure.
However, if this is your first infection, it could take up to six weeks for symptoms to appear. Even without visible symptoms, you can still spread the mites to others.
When to Get Medical Help
Contact your healthcare provider if you notice any possible scabies symptoms. Many skin conditions like eczema or dermatitis cause similar symptoms of itching and small bumps, so proper diagnosis is essential.
Your doctor can determine the exact cause and recommend appropriate treatment.
While over-the-counter antihistamines or lotions might temporarily relieve itching, they won’t eliminate the mites or their eggs. Only prescription medications can effectively treat scabies.
Causes
Scabies occurs due to a microscopic, eight-legged mite. Female mites create tunnels just beneath the skin’s surface where they deposit their eggs.
After these eggs hatch, the larvae move to the skin’s surface and develop into adult mites. These mites can then migrate to other body areas or transfer to other people.
The intense itching associated with scabies isn’t caused by the mites themselves. Rather, it results from the body’s allergic reaction to the mites, their eggs, and waste products.
Transmission of scabies happens primarily through:
- Direct skin-to-skin contact with an infected person
- Less commonly, sharing clothing or bedding with someone who has scabies
Important to note:
- Household pets do not have the ability to transmit scabies to humans.
- Animal scabies mites cannot survive or reproduce on human skin.
- Brief contact with a scabies-infested animal may cause temporary itching, but the mite will die within days without treatment.
Complications
Excessive scratching can damage your skin and lead to infections. Impetigo, a skin surface infection usually caused by staph or sometimes strep bacteria, is a common complication.
A more dangerous form of scabies called crusted scabies can affect certain vulnerable groups:
- Young children
- People with developmental disabilities
- Individuals with weakened immune systems (HIV, lymphoma, organ transplant recipients)
- Very ill people in hospitals or care facilities
- Elderly residents in nursing homes
Crusted scabies creates crusty, scaly skin patches covering large areas. It spreads rapidly and is resistant to conventional treatments. Doctors must treat it quickly with both oral and topical medications.
Regular scabies typically involves only 10–15 mites on the body. Crusted scabies can infest the skin with millions of mites. Strangely, people with crusted scabies may experience little to no itching despite the massive infestation.
When complications occur, prompt medical attention becomes essential to prevent further health problems and stop the spread to others.
Prevention
Scabies can be prevented from returning and from spreading to others by taking a few key steps. These steps focus on killing the mites and their eggs in your environment.
First, wash all clothing, towels, and bedding used in the last three days before treatment in hot, soapy water.
Then, dry these items using high heat to ensure the mites are killed. For items that cannot be washed at home, take them to be dry-cleaned.
For items that cannot be washed, place them in sealed plastic bags. Store these bags in an out-of-the-way location, like a garage, for about a week.
This effectively starves the mites, as they cannot survive for more than a few days without a human host.
Cleaning your home is also important. Vacuum all furniture, carpets, and floors thoroughly to remove any scales or crusts that might harbor mites.
This step is particularly crucial for people with crusted scabies, as their skin may shed more mite-containing material.
