Help!!

My 3year old boy this morning was complaining about his tooth while I was brushing them. I looked and and the bottom of his left gum was this strange white patch (I am a dental assistant) have never seen that before. A few hours later he couldn't eat and cried. I look again and he has these lumps on the inside of his lips and these blood spots on the top of his mouth and twards the back of his throat and gums....... What ??? He has an appt in a few hours but to stressed! Help!?