Don't want to get you worried, but he ended up in surgery (not emergency surgery) to have a thick mucus film scraped from his ribcage. The doctor told him it was likely a result of the pneumonia he experienced prior.
He's been fine since. Have you had any episodes of pneumonia or coughing fits from flu or other viral episode?
I hope that helps and wish you a speedy & healthy recovery, whatever it is.
None of those symptoms.