Just this afternoon my ds (10 months) has suddenly got a severe, constant cough. He hasn't had a cold or anything and now I'm listening to him coughing constantly on the monitor. I've never had a cough come on so quickly and it sounds really chesty. I feel worried about him but also over-anxious because it's only a cough. He's had a chest infection a few months ago, which cleared up completely with penicillin, but that set in over days, not one afternoon. Does anyone have any experience of this?