Pathogenesis (development of disease)
In scabies, transmission of the scabies mite (Sarcoptes scabiei variatio hominis) occurs through frequent close and prolonged skin contact. This prefers body parts where there is a thin horny layer and a relatively high temperature.
After the female mites have mated on the skin surface, the males die and the females dig tunnels in the stratum corneum (horny layer) of the epidermis where they lay a few eggs daily. They secrete many fecal pads, which are also stored in the tunnels. The eggs hatch into larvae after a few days, which crawl back to the surface.
Scabies ducts appear as comma-shaped redness that is slightly raised and above the level of the skin.
The scabies mite is dependent on humans and is viable for only 1-3 days outside of human skin.
Etiology (causes)
Biographic causes
- Socioeconomic factors – low socioeconomic status.
- Poor sanitary conditions
- High population density
- Poor medical care
Behavioral causes
- Poor hygienic conditions
- Frequent (intense) physical contact (e.g., cuddling with children; sexual intercourse).
- Transmission through shared bed linen, underwear, towels, etc. is theoretically possible
Disease-related causes
- Immunodeficiency (immune deficiency)
