intertrigo

from WordNet (r) 3.0 (2006)

intertrigo
    n 1: chafing between two skin surfaces that are in contact (as
         in the armpit or under the breasts or between the thighs)

from The Collaborative International Dictionary of English v.0.48

Intertrigo \In`ter*tri"go\, n. [L., fr. inter between + terere,
   tritum, to rub.] (Med.)
   A rubbing or chafing of the skin; especially, an abrasion or
   excoriation of the skin between folds, as in fat or neglected
   children.
   [1913 Webster]