No one can stop another person from smoking. Even though the habit is not good for anyone people are still able to choose if they want to smoke or not. If a person that smokes frequently comes around talk with them. Discuss the health repercussions that smoking presents and politely ask them to avoid smoking.
Think about the places that are frequently visited. Avoid places where people are able to smoke freely. If smoking is permitted outdoors or even in the establishment, like a bar, avoid going in. If these areas are not avoidable try to not linger. Spend the least amount of time possible around smokers.
Living with lupus does not need to be more difficult than it already is. Avoid situations where symptoms are irritated and aggravated. It may take time to get used to avoiding situations that exacerbate these symptoms. Once these situations are avoided life can be much more enjoyable.