title: Overwhelming pneumonia.
abstract: Overwhelming pneumonias remain an important cause of morbidity and mortality. These illnesses may be rapidly fatal; thus, many patients are treated empirically. Although the various etiologic agents cannot be differentiated on the basis of radiographic appearance, epidemiologic information may give a clue to the cause. Community-acquired overwhelming pneumonias are usually due to pyogenic bacteria (especially Streptococcus pneumoniae), mycoplasma, mycobacteria, and fungi. Hospital-acquired pneumonias are usually due to aerobic gram-negative bacilli. If the patient is immunocompromised, Pneumocystis carinii, Candida, and Aspergillus must be considered. Choice of optimal antimicrobial therapy requires that a specific etiology be identified. Gram's stain of sputum is often helpful in the diagnosis of community-acquired pneumonia. Invasive diagnostic techniques such as bronchoscopy and open lung biopsy are often required in nosocomial pneumonias and pneumonias in immunocompromised patients.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications / Q000382:microbiology; D001759:Blastomycosis / Q000150:complications; D003047:Coccidioidomycosis / Q000150:complications; D003428:Cross Infection / Q000503:physiopathology; D006192:Haemophilus Infections / Q000150:complications; D006193:Haemophilus influenzae; D006660:Histoplasmosis / Q000150:complications; D006801:Humans; D007877:Legionnaires' Disease / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D008171:Lung Diseases / Q000209:etiology; D009976:Orthomyxoviridae Infections / Q000150:complications; D010400:Penicillin G / Q000627:therapeutic use; D011014:Pneumonia / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology* / Q000382:microbiology; D011015:Pneumonia, Aspiration / Q000188:drug therapy / Q000503:physiopathology; D011018:Pneumonia, Pneumococcal / Q000175:diagnosis / Q000503:physiopathology; D011023:Pneumonia, Staphylococcal / Q000503:physiopathology; D011024:Pneumonia, Viral / Q000209:etiology; D013296:Streptococcus pneumoniae; D014376:Tuberculosis / Q000175:diagnosis
chemical_list: D010400:Penicillin G