CAT SKIN ERUPTION

Question
MY CAT HAS A SKIN ERUPTION FOR SOMETIME NOW ON ITS LOWER BACK SIDE,  BEFORE ITS TAIL.  ITS IRREGULAR IN SIZE, SORT OF LEAFY, ABOUT THE SIZE A QUARTER OF A DIME, RED AND SKIN COLORED, AND WHEN I ATTTEMPT TO VIEW AND TOUCH IT HE IS ANXIOUS AND IT APPEARS BY HIS REACTION... UNCOMFORTABLE

Answer
How long is sometime? If this cat is attacking his lower back (which is what it sounds like) then he needs to see a vet.

Some cats develop a neuritis right above their tail head. Neuritis is a painful nerve condition that often has no known origin.
They will work at it, chew on it, worry it because it hurts.

A vet will look at it and maybe do a skin scraping to see if it has any parasites such as mange or ringworm. He will also check for fleas since this is a popular place for a cat or dog to chew on when they have fleas.

If not then usually a course of steroids will ease the pain in that area.
Either way, you need to get your buddy in to see a vet soon.