Dr. Stengler: As I mentioned before, a very high percent of these people do have fungal overgrowth in their sinus. So what we do with these people which is a lot of them is use natural antifungal nasal sprays, things like grapefruit seed extract and oregano oil. They do come in nasal sprays, which gives a localized effect right in the sinus, killing the fungus right in the sinus. That's just what the Mayo Clinic found in their studies that most cases of chronic sinusitis are related to a fungal infection.Host: So how would you know that their acute or chronic sinusitis is due to fungal overgrowth and not something else?Dr. Stengler: A couple of things. First of all, what kind of treatments have they responded to? If they've been on some effective treatments for allergies, for example, and you're not getting much benefit, it's more apt to be a fungal problem. Or let's say they've been on antibiotics and that really hasn't helped then it probably is fungal. Or if people have been on steroidal nasal sprays, if you look at the package insert, one of the risk factors with those sprays is that you get fungal overgrowth in the sinus. If they were having problems before and now they're continuing to have problems, then you've got a double problem, because you have a fungal overgrowth and then whatever was causing their sinusitis before. We don't consider that a problem we just treat it. A lot of the time it's multifactorial. We'll treat their allergies, we'll give them the antifungal treatment, and the vast majority of people respond well.Also, someone who has a history of antibiotic use let's say you're a teenager on a lot of antibiotics for acne, or you're an adult who's been on antibiotics for different infections, and now you've got chronic sinusitis well, it's probably more related to a fungal problem given your history. So the history tells you a lot, and how they respond to treatments tells you a lot too.Host: Good information. Well, thank you, Dr. Mark.