While I would agree that there are some on the board who should see a doctor, I STRONGLY disagree with the statement about antibiotics. Antibiotics are misused these days and we are paying consequences for that through drug resistant infections and diseases.
A reaction to poison sumac is an ALLERGIC reaction. Now the rash could possibly become infected IF not properly cleaned and managed. That is a severe case and not likely what most are seeing. We're talking allergic reactions and should be treated as such.