My 5 year old has at least 3 black dry, crusty growths on his leg, chest, and chin. They are small, like skin tags. The crusty part protrudes out and comes off easily, but then it bleeds. He doesn't seem bothered by them and I've never seen him scratching or licking them. The vet was not concerned about them and just advised that I keep them clean with an antimicrobial cleanser. Has anyone else had this issue?