I began applying clindamycin 1% top lotion 2 days ago on back & face. now my vagina is itching terribly. could the med be the cause? no issues before.

Yeast infection?: Your symptoms suggest yeast infection, and sometimes yeast problems are triggered by antibiotics. However, probably not this time: it's unlikely enough clindamycin is absorbed through the skin; and 2 days is too soon. Best see a doctor to confirm the diagnosis. Or try an OTC yeast treatment (look for active ingredient ening in "azole") , but for sure see doc if it doesn't help in a few days.