56/m (ex-smoker) - is it common or rare for bacterial pneumonia (along with parapneumonic effusion) to cause pleural thickening?

It depends whether: it is diffuse(i.e. involving the whole lung) or focal pleural thickening. It would be exceedingly rare for bacterial pneumonia to cause diffuse pleural thickening, but relatively common to cause focal pleural thickening and/or effusion as a reaction to the adjacent infection.

Mgt.: Pleural thickening may occur as a result of chronic inflammation from infection and non infectious causes. The image may be uploaded for virtual consultation.