Hi there, my daughter (2) developed a large boil on her back a few days ago, she has a couple of smaller ones also that haven't gotten very big. My son yesterday came up with 3 of the same looking things right around his anus and they are extremely sore! They look like boils and I have treated them as such, using warm compresses, antiseptic and covering them. Why would they spread though, could this be something else?