1. Sarcoptes scabiei

2. Taxonomic classification
Class Arachnida
Sarcoptes scabiei (sarcoptic mange mite, itch mite)

3. Host spectrum
Domestic (sheep, goats, cattle, pigs, equids, dogs , rabbits) and wild animals, humans, other primates
Each host is considered to have its own strain or variety, e.g. Sarcoptes scabiei var. equi and Sarcoptes scabiei var. hominis

4. Geographic distribution
Probably worldwide

5. Morphology
Adults - rounded body; females mm long and mm wide, males mm long, mm wide; 8 short legs, posterior 2 pairs do not extend beyond the body margin; unsegmented pedicels; mouthparts have a rounded appearance.

7. Sarcoptes scabiei, the scabies or itch mite

9. Life cycle (stages)
Female mites tunnel into the epidermis , lay 3-5 eggs per day for a total of eggs
Six-legged larvae hatch from eggs
Larvae and nymphs (proto- and deuto-) burrow into the stratum corneum and form pockets where they molt and feed
Adult males and females develop and mate
Life cycle requires 2-3 weeks to complete

12. Site of infestation
Skin (epidermis); females, eggs, larvae and nymphs in tunnels or pockets, males on the skin surface.

13. Pathogenesis/clinical signs
Initial lesions occur on the hand, elbows, axillary or inguinal regions
Lesions are initially erythematous, then become papular; papules rupture and skin becomes crusty
Alopecia, thickening of the skin, pruritus
Secondary bacterial infection, allergic reaction, self-mutilation may occur

15. A severe case of scabies of the hand.

16. Crusted appearance on hands

17. Treatment
Lindane shampoo or dip, phosmet (ParamiteR), or Amitraz (MitabanR)
ivermectin weekly for four weeks orally or subcutaneously

18. Public health significance
Humans may be infested with the strains from animals and these infestations may be mild to intensely pruritic, but they are self-limiting.