You might have developed an allergy
to doxycycline. I suggest to stop doxycycline and why are you taking doxycycline? In a few days to weeks after stopping doxycycline the swelling and itchiness will go away. If it gets worse you might need to see an allergologist or a dermatologist
cause there are fatal cases of allergies.
I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications at: http://www.HealthcareMagic.com/doctors/dr-manuel-c-see-iv/66014 I would gladly help you. Best wishes.