Scabies - Find a Specialist and Get Information

Scabies is an infectious disease that occurs worldwide. It spreads rapidly in places where people live in close quarters (families, nursing homes, schools, and daycare centers). Scabies is particularly common in areas with low hygiene standards. The prevalence ranges from 1 to 30 percent, depending on the environment.

Scabies is transmitted through close physical contact, particularly during sexual intercourse. Therefore, scabies is classified as a sexually transmitted disease (STD). According to the Infection Protection Act, scabies must be reported if people in communal settings such as schools or preschools contract the disease.

The causative agent of scabies is a parasite called Sarcoptes scabiei. It belongs to the arachnid family and is about 0.2 to 0.4 millimeters in size. It has a translucent body and eight legs arranged in pairs. It also has powerful jaws.

The female scabies mite burrows into the skin, feeds there, and lays 1–3 eggs daily. Larvae hatch from these eggs a few days later, which in turn develop into sexually mature scabies mites within two to three weeks. In this way, they continue to multiply rapidly.

The scabies mite Sarcoptes scabiei causes scabies @ Aliaksei /AdobeStock

In most cases, scabies is transmitted through close physical contact with infected individuals. Infection is therefore particularly likely during sexual intercourse. 

Sharing bedding, mattresses, blankets, pillows, towels, or clothing can also lead to infection.

Other possible sources of infection include stuffed animals, thermometers, and blood pressure cuffs. 

The risk of infection is highest in places where hygiene is poor or where people live together in close quarters. Examples include nursing homes, homeless shelters, daycare centers, and schools.

After the initial infection with scabies, it takes two to six weeks for the first symptoms to appear.

Symptoms include an itchy rash and widespread, inflammatory skin lesions.

If a person becomes reinfected with scabies, the first symptoms appear after just a few days.

Scabies mites prefer to infest areas of the body with a thin layer of skin and a high temperature. 

These include, in particular:

• The spaces between the fingers
• The wrists
• The elbows
• The crooks of the arms
• The knee
• The chest and armpit area
• The area around the navel
• The buttocks
• The genital area
• The penis

In rare cases, the rash spreads to the arms, thighs, fingers, palms, soles of the feet, abdomen, or back.

Day 6 after a scabies infection

Typical symptoms of scabies include:

• Nodules
• Pustules or papules
• Scaly, swollen patches of skin
• Scaly, crusty skin inflammation
• Formation of blisters

Intense itching is also one of the signs of scabies. It is particularly unbearable for those affected at night. Patients scratch themselves more frequently. This leads to scratched areas of skin and superficial skin lesions, which in turn provide an ideal breeding ground for bacteria. As a result, a purulent rash develops.

If a patient suffers from severe nighttime itching and the characteristic rash, scabies is suspected.

In this case, the patient should consult a dermatologist and undergo a thorough examination. 

First, the doctor examines the affected area with a special magnifying glass to look for burrows and scabies mites. 

The burrows can be made visible using the ink test. To do this, the doctor applies a drop of water-soluble ink to one of the papules. He then uses a scalpel or a sharp spoon to take a sample from the burrows or papules. Under the microscope, the doctor examines the sample to see if any definitive microscopic pathogens are detectable.

Preferred sites on the body for mite infestation

Treatment involves a cream that the patient applies once to the entire body (except for the face). When used correctly, the cream kills the scabies mites and prevents reinfection. The skin heals within a few days or weeks.

The treatment of choice is an ointment containing the active ingredient permethrin, a synthetic insecticide. Other available treatments include creams or ointments containing the active ingredients benzyl benzoate and crotamiton.

To prevent reinfection with scabies, it is advisable to:

• Treat everyone in your immediate circle. Since the first symptoms do not appear until several weeks later, you should also include people who do not yet have any symptoms.
• In addition, you should wash bedding and clothing at 60 degrees Celsius or air them out for four days. This kills scabies mites, which survive for a maximum of three days without a host.
• Freezing shoes and textiles in the freezer or sealing them in plastic bags is also an effective way to kill scabies mites.
• You should also thoroughly vacuum beds, armchairs, carpets, and floors.

If left untreated, scabies worsens over time and becomes chronic. Treatment for scabies is therefore essential. Proper treatment leads to a cure in most cases. After the scabies mites have been killed, the itching may persist for several weeks. This is caused by the body’s allergic reaction to the dead mites and their feces in the skin. It takes some time for the skin lesions to heal.