The Collaborative International Dictionary
Canker rash
Rash \Rash\, n. [OF. rasche an eruption, scurf, F. rache; fr. (assumed) LL. rasicare to scratch, fr. L. radere, rasum, to scrape, scratch, shave. See Rase, and cf. Rascal.] (Med.) A fine eruption or efflorescence on the body, with little or no elevation.
Canker rash. See in the Vocabulary.
Nettle rash. See Urticaria.
Rose rash. See Roseola.
Tooth rash. See Red-gum.
Canker rash
Canker rash \Can"ker rash`\ (Med.) A form of scarlet fever characterized by ulcerated or putrid sore throat.
Wiktionary
canker rash
n. (context medicine dated English) A form of scarlet fever characterized by ulcerated or putrid sore throat.