Bacterial pneumonias can occur at any stage of disease. PCP is more gradual in onset. It typically comes on over weeks, while bacterial pneumonia comes on over days. With other types of pneumonia, cough tends to be a bigger problem than shortness of breath. The cough of PCP is usually a dry cough, whereas people with bacterial pneumonia cough up lovely gobs of yellow or green or brown sputum.
Bacterial pneumonias tend to respond faster to treatment.
With PCP, people often get worse for a few days before the medicines kick in. The x-ray appearance of PCP is usually different. With PCP you see involvement of both lungs, whereas with bacterial pneumonia only certain sections of the lung may be involved People with bacterial pneumonia often have chest pain when they breathe. PCP is usually treated for 21 days. For people who can't take sulfa drugs, there are a number of alternatives.