Scabies (Itch mite or Sarcoptes scabiei)
Scabies is caused by itch mite or Sarcoptes scabiei.
Transmission to man is through transfer of impregnated
female mites through—
(1) skin-to-skin contact with an infested person, or
(2) rarely spread indirectly by sharing their items such as clothing, towels, or bedding. Scabies can spread easily under crowded conditions where close body and skin contact is common.
Initial infestation is asymptomatic for two months although
the person can still transmit scabies during this time. In case
of reinfestation, symptoms appear much earlier in 1–4 days.
Primary infestation: The mites burrow into the upper
layer of the skin but never below the stratum corneum.
Mites burrowing under the skin cause a rash, which is
most frequently found on the hands, particularly the
finger web spaces; wrist folds, elbow or knee; the penis;
the breast; and/or the shoulder blades (Fi. A7.1A)
Severe itching is the most common presentation,
especially at night and over body surface, including areas
where mites are undetectable.
Crusted (Norwegian) scabies: This is a severe form of scabies,
seen among persons who are immunocompromised,
elderly, or institutionalized.
●It is characterized by vesicles and formation of thick
crusts over the skin, accompanied by abundant mites
but only slight itching
● Secondary bacterial infections are common