Pneumonia is a disease characterized by inflammation and congestion of the lungs. Infection with any of a variety of microorganisms is the typical cause, but sometime the condition is related to an allergic reaction or inhalation of fluid, food, or certain gases.

When pneumonia is restricted to a single lobe of the lung or to a portion of a lobe, it is referred to as lobar pneumonia. Pneumonia that has more extensively spread through the lungs is known as bronchopneumonia. The Gram-positive bacterium Streptococcus pneumoniae (also called pneumococcus) is responsible for most cases of lobar pneumonia. Other leading causes of the disease include infection with Mycoplasma, Legionella, or other Gram-negative organisms.

Pneumococcal lobar pneumonia is most prevalent during the winter months, but can occur at any time. Those most commonly and seriously affected by the disease are children and the elderly. Notably, the presence of pneumococci does not always result in the development of pneumonia, some studies indicating that as many as one-fourth of healthy individuals are carriers of the bacteria.

Since most cases of lobar pneumonia are pneumococcal in origin, they are typically treated with antibiotics, especially penicillin. Before the discovery of such drugs, the disease was associated with a high death rate. Medical advances have made it possible for most individuals diagnosed with pneumonia to recover. However, some strains of bacteria have developed resistance to penicillin and other antibiotic medications. Infections with such bacteria may necessitate special sensitivity testing in order that the best mode of treatment may be determined.

An acute upper respiratory infection or cold often precedes the onset of pneumococcal lobar pneumonia. The symptoms that develop and the extent of their severity depend on the age and general health of the individual affected as well as a number of other factors, but often include a cough (dry or producing phlegm or blood), fever, fatigue, chills, shaking, and painful, labored breathing. Nausea, vomiting, and painful or tender muscles also sometimes occur.

Lobar Pneumonia at 20x Magnification - People who are at greatest risk of developing pneumonia are generally advised to receive the pneumococcus vaccine, which currently provides protection from the types of the bacteria that are responsible for about 90 percent of the most severe pneumococcal infections.

Lobar Pneumonia at 40x Magnification - In addition to medicine, many patients with pneumonia are prescribed analgesics to alleviate pain associated with breathing, coughing, or other symptoms of the disease. Bed rest and plenty of fluids are also considered key to supportive care.

Lobar Pneumonia at 10x Magnification - Many cases of pneumonia necessitate the patient’s hospitalization, but sometimes individuals are able to be treated simply by a general practitioner or never even realize they have an infection, in which case the disease is often referred to as walking pneumonia.