Acute inflammation of the walls of the terminal bronchioles that spreads into the peribronchial alveoli and alveolar ducts. It results in the creation of foci of consolidation, which are surrounded by normal parenchyma. It affects one or more lobes, and is frequently bilateral and basal. It is usually caused by bacteria (e.g., Staphylococcus, Streptococcus, Haemophilus influenzae). Signs and symptoms include fever, cough with production of brown-red sputum, dyspnea, and chest pain.

Inflammation of the lung parenchyma that is associated with BRONCHITIS, usually involving lobular areas from TERMINAL BRONCHIOLES to the PULMONARY ALVEOLI. The affected areas become filled with exudate that forms consolidated patches.