My dr. prescribed me systemic vibramycin (doxycycline) for a mild cellulitis in my upper eyelid dt.mosquito bite.is this effective?!!

Precautionary: The swelling from a mosquito (and other insect) bites is usually an allergic reaction to the proteins and toxins in the bite and rarely due to infection. Vibramycin (doxycycline) in this context is precautionary but usually not necessary. You might need and anti-histaminic if the swelling persists. Infection would be denoted by a pus filled pocket but again this is rare.

Doubtful: Swollen, red skin after mosquito bite, especially on an eyelid, is a local reaction to mosquito saliva. It is NOT cellulitis, therefore the antibiotic is ill- considered. Furthermore, why Vibramycin brand rather than generic doxycycline? Probably no harm, but always some chance of unwanted effects as well as waste of money if taking antibiotic when no infection is present.