Being tx'd w/antibiotics for cellulitis of nostril, which has a large swelling and just started draining pus. does this need to be drained by doc?

Technically...: The definitive treatment for an abscess is drainage, so it does need to drain. If you just started antibiotics today, and drainage is minimal, you can monitor for another day or two. If you've been on meds for a few days and the drainage just started, you should get evaluated because your cellulitis has progressed. Call the doctor's office and review the timeline and status with triage nurse!