What would cause an occipit lymph node to swell bac up after antibiotic therapy node goes away w/antibiotic but comes bac a week or 2 later same size?

Followup: Enlarged ln may not be due to infection. It is best to reexamine the ln, checking for resolution/enlargement. Biopsy may be indicated with progressive enlargement.

Lymphadenopathy: Enlarged lymph nodes are those that are either trying to do their job in the immune system, or those that have been taken over by some preexisting disease, like tumor. Yours sounds as if there may be a persistent focus of inflammation, which when suppressed results in reduction of the size of the node, following which it may be acting up again, or the lymph node is simply cleaning up the mess.