Pulmonary Embolism (PE): This is often considered the most likely diagnosis for pleuritic chest pain due to its relatively high prevalence and the fact that it can present with sudden onset of sharp, stabbing pain that worsens with deep breathing or coughing. The right side can be affected if the embolism lodges in a branch of the right pulmonary artery.

Pneumonia: Especially if it involves the right lower lobe, pneumonia can cause pleuritic chest pain due to inflammation of the pleura. Symptoms may include fever, cough, and sputum production in addition to the pain.
Pleurisy: Inflammation of the pleura itself, which can be due to viral infections, can cause sharp pleuritic pain. It's often accompanied by a friction rub heard on auscultation.
Costochondritis: Inflammation of the cartilage that connects the ribs to the sternum can cause sharp pains that may worsen with deep breathing or movement, mimicking pleuritic pain.

Pulmonary Embolism (already mentioned but bears repeating due to its critical nature): The risk of missing a PE is high if not considered, as it can be fatal if not treated promptly.
Aortic Dissection: Although less common, an aortic dissection can cause severe, tearing chest pain that may be pleuritic in nature if it involves the descending aorta. It's a medical emergency.
Pneumothorax: A collapsed lung can cause sudden, severe pleuritic pain and shortness of breath. It requires immediate medical attention.

Pulmonary Infarction: While less common than other causes, pulmonary infarction (death of lung tissue due to lack of blood supply) can occur, especially in the setting of PE, and cause pleuritic pain.
Diaphragmatic Hernia: A rare condition where part of the stomach or intestine bulges into the chest cavity, which can cause severe, pleuritic-like pain, especially after eating or straining.
Bornholm Disease (Pleurodynia): A viral infection that causes severe, stabbing chest pain, typically affecting the intercostal muscles, and can mimic pleuritic pain.