Source : Webster's Revised Unabridged Dictionary (1913)

Urtication \Ur`ti*ca"tion\, n. (Med.)
   The act or process of whipping or stinging with nettles; --
   sometimes used in the treatment of paralysis.

Source : WordNet®

urtication
     n 1: an itchy skin eruption characterized by weals with pale
          interiors and well-defined red margins; usually the
          result of an allergic response to insect bites or food
          or drugs [syn: {urticaria}, {hives}, {nettle rash}]
     2: a sensation of having been stung by nettles