The Collaborative International Dictionary of English v.0.48:

Sudamina \Su*dam"i*na\, n. pl., sing. Sudamen. [NL. sudamen,
   -inis, fr. sudare to sweat. See Sweat.] (Med.)
   Minute vesicles surrounded by an area of reddened skin,
   produced by excessive sweating.
   [1913 Webster]