"i took doxycycline for severe cystic acne for six months.  my skin cleared up beautifully, however once i stopped taking it, within a week, my skin broke out 10x worse than it was before i started taking doxycycline.  i ended up not only with the usual painful cystic acne, but also on top of that developed acne rosacea... so my face was lumpy, painful, and terribly red."