Used to have a big ragweed problem in East Texas, Dallas area. With me it became sinusitis infections which was like sore throat & sinuses and cold symptoms. At the time I was trying to get riding time in for centuries and antibiotics weren't finishing it off. So I went to a different doctor and he would give me kenalog shots up the nose which actually gave me enough respite from that particular symptom to allow me enough riding time for a couple of my faster centuries.

It's a form of steroid though and don't really know if it's the thing for either congestion or bronchitis. Up here in Washington state my similar but much milder sinusitis is usually handled by moderate use of prescribed "Nasonex" spray, but only when I need it as it's also a steroid.