Source : Webster's Revised Unabridged Dictionary (1913)

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.

   2. Any itching eruption.

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

   4. A constant irritating desire.

            An itch of being thought a divine king. --Dryden.

   {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} (Zo["o]l.), 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}. (Zo["o]l.) 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.