(l) leg above back of ankle had pimple/ blister, itchy. Used cortisone cream. Today oozing liquid. Cleaned, & used nystatin. Very red/sore. (day 2) dx?

Insect bite? Hard to know what this is without seeing it. If the area of redness and warmth and tenderness continues to increase would recommend seeing a doctor asap.
What color ooz. It could be an infection, ingrown hair, or friction blister depending on location and the ooz! there are many possibilities and you need to see a podiatrist or your doctor for correct diagnosis and treatment plan.