In scabies – colloquially called scabies – (synonyms: Acarodermatitis; Infestation by scabies mites; Infestation by Sarcoptes scabiei; Infestation by scabies; Eczema scabiosum; Eczematized scabies; Norwegian scabies; Scabies with post-scabies eczema; ICD-10 B86: Scabies) is an infectious disease caused by scabies mites (Sarcoptes scabiei variatio hominis; parasite) that affects the skin. It is colloquially referred to as scabies.
The scabies mite belongs to the arachnids (Arachnida), which are members of the Sarcoptidae family.
Scabies infestation (lat.: infestare, to attack; colonization of an organism with a parasite that does not reproduce in the host organism) is one of the sexually transmitted diseases (STD). However, transmission occurs primarily through intense close and sufficiently prolonged contact.
Occurrence: The infection occurs worldwide. It occurs mainly in areas where many people live in confined spaces and where hygiene is poor. In Germany, it mainly affects people living in old people’s homes and nursing homes. 15% of the population in emerging and developing countries are affected by scabies.
The contagiousness (infectiousness or transmissibility of the pathogen) is medium. Scabies mites can live only a short time without a host and this only at low temperatures and high humidity. At room temperatures of 21°C and relative humidity of 40-80%, scabies mites are unlikely to be infectious for more than 48 hours.
Direct transmission can be distinguished from indirect transmission (route of infection). Direct transmission occurs through prolonged and close skin contact between two people, e.g. during sexual intercourse. Therefore, scabies also belongs to the sexually transmitted diseases (STD) or STI (sexually transmitted infections). Short skin contacts such as shaking hands are not sufficient for transmission. Indirect transmission occurs through contact with infected skin flakes.
Human-to-human transmission: Yes (skin-to-skin contact) [requires extensive skin contact over 5 to 10 minutes because of the usually low mite count].
Incubation period (time from infection to onset of disease) is 2-5 weeks for initial infection and 1-2 days for reinfestation.
Frequency peak: Scabies affects all age groups.
Course and prognosis: Scabies quickly manifests as an extremely pruritic dermatosis (skin disease). Under adequate therapy, the course of scabies is benign. However, the pruritus (itching) persists for some time after the end of therapy. Note
- Sick infants, severe secondary bacterial infections (infection that is additional and with a different pathogen than that of the initially present infection) and the clinical picture of a scabies crustosa (see below “Complaints – Symptoms”) require inpatient therapy.
- Still for weeks to months can occur after successful treatment papules (nodule-like change on skin) and nodes that persist. These are postscabial granulomas (immune reaction to the mite protein), which are no longer contagious, because they no longer contain mites.
In childhood, recurrences (recurrence of the disease) are common.
In Germany, the disease is not reportable under the Infection Protection Act (IfSG). However, people with scabies or suspected of having the disease are not allowed to work in care facilities if they have contact with those being cared for. Also, if the care recipients themselves are infected, they must not enter the community facility.
