<prompt> Common presenting symptom of pneumocystis carini pneumonia IsCavity on X-rayHaemoptysisBreathlessnessPurulent sputum  <response>: The key presenting symptom of PCP is progressive dyspnoea.Dry cough fever are common.Physical findings include tachypnoea,tachycardia,and cyanosis.Chest X ray shows typical ground-glass interstitial infiltrates in the perihilar regions.Pneumatoceles may occur and rupture,resulting in a pneumothorax. Reference: Davidson edition23rd pg 585 