Is smoking with a missing tooth making the infection worse?

Affects healing: If you are referring to a recently extracted tooth socket, then it will delay the healing and possibly contribute to a dry socket complication. You should have recieved instructions telling you not to smoke until healing completed. The heat, and chemicals are a deterrant to healing and the sucking action can pull the blood clot out and you can get a dry socket. Hope this helps.

Shouldn't be one...: A tooth is a catalyst for an infection, if the tooth was recently removed due to the infection, smoking doesn't help the site heal, rather the opposite. If you have an infection present and it's not related to a recently removed tooth, smoking is the least of your worries. Go see your dentist and address it. It can spread throughout the rest of your body!