Shivering, Sweating, Burning Hot, Enlarged Lymph Nodes, Rashes. Taken Doxy, Ibrufen. What Could Be The Reason?

My husband began getting the shakes suddenly on sat night. He spent the evening cold and shaking then sweating profusely and burning hot. He felt unwell on Sunday sweating and aching all over. His lymph nodes are enlarged behind his ears and a strange rash appeared on his head. On mon he went to doctors and had bloods taken and was given doxy and ibrufen. So far sat and sun nights he sweated heaps. Enough to change bed sheets. Today being tues. he seemed a little better had day off work. Sweating was a little less. By this afternoon his forehead and left eye lid had swollen. We raced bk to doctors who gave him telfast. Face looks rather strange. We r in bed now for only 10 mins and sweating has started again. I have never seen anything like this. Any ideas??