The scabies (mediz. Scabies) is an infectious skin disease caused by mites. The infection usually happens through close skin contact with patients. The parasites and their excretions trigger an allergic reaction with a rash and severe itching. Scabies can be treated very effectively. Read here the most important information about the infection, symptoms and treatment of scabies.

ICD codes for this disease: ICD codes are internationally valid medical diagnosis codes. They are found e.g. in medical reports or on incapacity certificates. B86ArtikelübersichtKrätze

  • risk of infection
  • symptoms
  • treatment
  • causes
  • description
  • Examinations and diagnosis
  • forecast

Scabies: Short overview

  • Infection: over prolonged, intense physical contact (hug, intercourse), sleeping together, caring for the sick, close cohabitation, sharing towels or clothes, playing games together
  • symptoms: small pustules / blisters, small, reddish-brown mite glands on warm parts of the body (between fingers and toes, inner margins, underarm area, around the nipple vestibule, penis shaft, anal region), intense itching, burning (at night increased) allergy-like rash.
  • Treatment: externally applied insecticides (whole body treatment), tablets
  • Forecast: usually very fast and reliable treatment success, but skin irritations can persist even longer. No immunity, repeated infections possible
  • Reporting requirements: to the health authority if several people are involved in community facilities (if a connection is likely)
  • Important: Simultaneous co-treatment of all contact persons of the patient required!
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Where can you catch scabies?

Infectious diseases are contagious, so is scabies. "Contagion" or "infection" in connection with scabies is sometimes referred to as "infestation", a term that describes a colonization of the body with parasites.

The transmission of the scabies is done by direct skin contact with diseased persons. So there is usually no (animal) intermediate host, as is the case with many other parasitic diseases. There must also be prolonged body contact to allow the mites to move from one host to the next. This is the case, for example, during intercourse, which is why scabies are also counted among the sexually transmitted diseases.

Typical transmission paths are also, for example:

  • sleeping together in a bed
  • Body care of toddlers by parents or the sick by caregivers
  • Caresses and cuddling
  • playing together

Contrary to popular belief, contaminated items play less of a role as an infection path. The mites lose their infectiousness within a few hours at room temperature. However, infection is possible, for example, through contaminated carpeting, shared bedding, clothing or towels. Even furniture or medical instruments with which the patient came into contact should always be cleaned.

Personal hygiene plays only a minor role

What according to recent studies, however far less important than expected, is the body hygiene. Thus, the risk of infection can hardly be reduced even with intensive personal hygiene. However, the body care plays a role in the strength of the expression of the scabies. Because the worse the body hygiene, the more mites frolic on the skin.

Short touches such as shaking hands are usually not enough to get infected with scabies. Nevertheless, the body contact with infected people without protective clothing should be avoided as far as possible.

Beware of the bark stains

A special feature is the Scabies norvegica dar. In this form of scabies affected suffer from a very dense mite infestation, mostly due to an immune deficiency. While in patients with normal scabies rarely more than 12 to 30 mite gullies are found at the same time, with the bark scraps several million active animals can be present.

The more mites, the higher the risk of infection. Any dandruff that a person with Scabies norvegica loses can be covered with several thousand mites. It is therefore all the more important to isolate patients and to wear protective clothing when dealing with them and in their environment.

Several weeks incubation period

In case of scabies, the incubation period may be several weeks: The typical scabies symptoms occur only two to five weeks after the first infection. With renewed contagions it comes already after few days to symptoms. Without therapy, the scabies are usually not completely cured, although cases of spontaneous healing are described.

Is there a duty to report scabies?

According to the Infection Protection Act, scabies are then reportable if they break out in community facilities. These include, for example:

  • kindergartens
  • Old people's and children's homes
  • schools
  • Refugee shelters, asylum seeker homes

The management of the facility must, as soon as it has knowledge of the presence of scabies, report them to the responsible health authority and also indicate the personal data of the patient (s). A basic obligation to report individual cases does not exist, however, in the case of two or more diseases with a suspected connection.

Scabies may not work in community facilities or have contact with those who are cared for.

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Scabies: Symptoms

Although the symptoms of scabies are typical, they are often unrecognized and confused with allergies or other illnesses. This may also be due to the fact that scabies have become very rare in Germany.

One distinguishes between direct and indirect symptoms of scabies:

Direct scabies symptoms

The so-called Milbengänge: The parasites dig small tunnels in the upper skin layer, which can show as a maximum of two to three centimeters long, irregularly serpentine ("comma-shaped") Milbengänge. When visible to the naked eye, they appear brownish-reddish.

Often, despite an infection, no passages can be detected with the naked eye. For example, if they are covered by other skin conditions, or the skin color is very dark.

The number of mites can vary depending on the stage of the disease. An otherwise healthy person will normally have no more than eleven to twelve miles, while in the skin of immunocompromised patients there may be tens of thousands or even millions (scabies crustosa).

Even with people with a healthy immune system, there may be a few hundred mites at times, which is usually the case three to four months after infection. After a short time, however, the number of mites goes down sharply.

Personal hygiene has only a minor influence on the number of mites. Badly well-groomed people may have some more mites in their skin.

Indirect scabies symptoms: The response of the human immune system to the itch mites is most of the trigger of the main symptoms. Itching is the classic scabby symptom, scratching has given the disease its name:

  • severe itching (pruritus) and / or slight burning of the skin
  • Blisters and pustules, possibly nodules. The blisters are filled with fluid or pus, but contain no mites. They can be single or in groups.
  • Rashes (Exantheme)
  • Crusts (after the bursting of the liquid-filled bubbles)

As with some other skin diseases, the itching of scabies at night in a warm bed is usually much stronger than during the day.

Where do the scabies symptoms show up?

The pregnant mite females drill passages into the skin to lay their eggs there. They prefer to find places where the skin is thin and particularly warm. These include:

  • the areas between the fingers and toes (interdigital folds) as well as the inner foot edges
  • the wrists
  • the axillary regions
  • the nipples and the navel
  • the penile shaft and the area around the anus

The back is rarely affected, the head and neck are usually spared. In infants and toddlers, however, the mite infestation can also occur on the face, on the hairy head and on the soles of the feet and feet.

The typical scabies symptoms are seen mainly where the mites sit. But they can also go beyond that and in some cases even affect the entire body. The latter is especially true for rashes (Exantheme).

Special forms of scabies and their symptoms

The scabies can, depending on severity and type of symptoms, in certain special forms:

  • Scabies in newborns and infants
  • well-kept scabies
  • nodose scabies
  • bullous scabies
  • Scabies norvegica (crustosa), also called bark scraps

In the context of some special forms of the disease, the mentioned scabies symptoms can vary or more can be added.

Well-groomed Scabies

For affected people who use intensive body care including the use of cosmetics, the skin lesions described are often only discreet, which can make the diagnosis more difficult. One speaks then of a well-kept Scabies.

Nodose and bullous scabies

The nodular scabies are characterized by the development of very itchy reddish-brownish nodules. These do not contain mites and sometimes persist for months after successful parasitic killing.

If there are many smaller and larger blisters (Vesiculae, Bullae) within the scabies, then there is talk of a bullish scabies. This form is increasingly found in children.

Scabies norvegica (Scabies crustosa)

The above-mentioned bark scabies (Scabies norvegica or S. crustosa) differs significantly from the normal variant of scabies due to the massive mite infestation. There is erythrodermia on the whole body as well as the formation of small and medium-sized scales (psoriasiform picture).

Thick layers of the cornea (hyperkeratosis) develop on the palms and feet. Fingers, backs of hands, wrists and elbows can be formed with bark that is up to 15 millimeters thick. Under these crusts (which, incidentally, are not caused by bursting blisters), the skin appears red and moist-shiny. The barks are usually limited to a specific area, but may also spread to the scalp, back, ears and soles.

It should be noted that the itching - the most typical of scabies symptoms - can often be completely absent.

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Scabies: Treatment

The scabies treatment is quick, painless and uncomplicated - at least in most cases. However, in certain circumstances, the treatment of parasitic skin disease can be difficult, for example when several people are affected within a community facility. The state of the patient's immune system also plays a role, and in some patient groups there are deviations in the treatment concept.

The main goal of scabies treatment is to kill off the parasites that cause the disease. There are various medicines available for this, all of which, with one exception, are applied directly to the skin:

permethrin: The insecticide is applied as a cream on the entire body surface and is considered the drug of choice. Only in exceptional cases does the doctor resort to alternatives.

allethrin: Used as a spray in combination with piperonyl butoxide, but only used if permethrin therapy is not possible because of complications.

benzyl benzoate: Although has a high activity against the mites, but is also used only in exceptional cases due to the relatively complicated application.

Ivermectin: It is also used as a worm remedy and, in contrast to the other medicines, the scabies treatment is taken in tablet form.

Until a few years ago, lindane was used even more frequently as an alternative to permethrin, but now largely dispensed with since this insecticide is quite toxic.

In developing countries, in addition to cost-effective benzyl benzoate, scabies treatment also increasingly uses sulfur-containing preparations. In Germany, these play because of the unpleasant odor when applying and the potential toxicity no longer matter.

According to studies, the most common drugs for treating scabies rarely cause side effects such as skin rashes, diarrhea and headaches.

Allethrin may cause serious respiratory complications in patients with pre-existing conditions of the bronchi and lungs and should therefore not be used in these individuals.