What Are The Painful Boils On The Back?

hi doctor, my grandpa is 70++ years old.. recently he having some like boils on this back of his body.. yesterday he complaining he having pain due to the presence of the boils. I tried to pinch the boils. and dark brown of exudate were out from the boils. the more i pinched the more its been out. and now the boils are disappear and no more exudate.