The Collaborative International Dictionary of English v.0.48:

Scabies \Sca"bi*es\, n. (Med.)
   The itch.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Itch \Itch\, n.
   1. (Med.) An eruption of small, isolated, acuminated
      vesicles, produced by the entrance of a parasitic mite
      (the Sarcoptes scabei), and attended with itching. It is
      transmissible by contact.
      [1913 Webster]

   2. Any itching eruption.
      [1913 Webster]

   3. A sensation in the skin occasioned (or resembling that
      occasioned) by the itch eruption; -- called also
      scabies, psora, etc.
      [1913 Webster]

   4. A constant irritating desire.
      [1913 Webster]

            An itch of being thought a divine king. --Dryden.
      [1913 Webster]

   Baker's itch. See under Baker.

   Barber's itch, sycosis.

   Bricklayer's itch, an eczema of the hands attended with
      much itching, occurring among bricklayers.

   Grocer's itch, an itching eruption, being a variety of
      eczema, produced by the sugar mite (Tyrogluphus
      sacchari).

   Itch insect (Zool.), a small parasitic mite (Sarcoptes
      scabei) which burrows and breeds beneath the human skin,
      thus causing the disease known as the itch. See Illust. in
      Append.

   Itch mite. (Zool.) Same as Itch insect, above. Also,
      other similar mites affecting the lower animals, as the
      horse and ox.

   Sugar baker's itch, a variety of eczema, due to the action
      of sugar upon the skin.

   Washerwoman's itch, eczema of the hands and arms, occurring
      among washerwomen.
      [1913 Webster]

WordNet (r) 3.0 (2006):

scabies
    n 1: a contagious skin infection caused by the itch mite;
         characterized by persistent itching and skin irritation;
         "he has a bad case of the itch" [syn: scabies, itch]

Moby Thesaurus II by Grady Ward, 1.0:

77 Moby Thesaurus words for "scabies":
   Texas fever, acne, acne vulgaris, anthrax, aphthous fever, bighead,
   black quarter, blackleg, blackwater, blind staggers, bloody flux,
   broken wind, cattle plague, charbon, dermamycosis, dermatitis,
   dermatosis, distemper, eczema, elephantiasis, epithelioma,
   erysipelas, erythema, exanthem, foot-and-mouth disease, gapes,
   glanders, heat rash, heaves, herpes, herpes simplex, herpes zoster,
   hives, hog cholera, hoof-and-mouth disease, hydrophobia, impetigo,
   itch, jungle rot, leprosy, lichen, lichen primus, liver rot, loco,
   loco disease, locoism, lupus, lupus vulgaris, mad staggers,
   malignant catarrh, malignant catarrhal fever, malignant pustule,
   mange, megrims, miliaria, milzbrand, paratuberculosis, pemphigus,
   pip, prickly heat, pruigo, pruritus, pseudotuberculosis, psora,
   quarter evil, rabies, rinderpest, ringworm, rot, sheep rot,
   shingles, skin cancer, splenic fever, staggers, stringhalt,
   swine dysentery, tetter