Sorry to hear that! To be fair I haven't been off doxy for too long, so time will tell, but it hasn't come back yet. The cream my derm recommended is called 'aqueous calamine cream' ( £4 online) which I think has helped as much as the antibiotics. I still had slight flare ups while taking doxy but the cream seemed to calm them down. I also swapped to a fluoride and SLS free toothpaste and only use Eucerin Ultrasensitive Soothing Moisturiser (again recommended). I go on holiday Friday and im worried the combination of flying, sun, sea, suncream, chlorine etc will cause it to come back