I get seasonal allergies that irritate my chest more than my sinuses, and her fits are symptomatic of letting that irritation turn into infection. I take the modern day version of pseudo fed for mine when it flares up. Not saying that that is what she has, but untreated, these chest irritations can progress to bronchitis or even pneumonia.
Pseudo fed? Is that Sudafed? Or is it a fake version of the Federal Reserve?