The erythema appears in patches, and as it is most common near the end of the winter it is known as the "spring eruption" or "spring itch."
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
Chafing, which is another form of erythema, is occasionally seen on the udders of cows from rubbing by the legs; chafing between the legs is not uncommon among fat steers.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
In simple erythema the epidermis alone is affected; when it becomes chronic, fissures form and extend into the corium, or true skin.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler