Pneumonias

 DEFINITION

Inflammatory consolidation of the lung.

AETIOLOGICAL CLASSIFICATION

I.             Infective:

1. Bacterial: (the most common)

• Sreptococcus pneumoniae. (50%)

• Hymophilus influenza. (5%)

• Mycoplasma pneumoniae. (5%)

• Legionella pneumophila. (2%)

• Staphylococcus aureus. (2%)

• Klebsiella pneumoniae. (rare).

• Anerobic bacteria. (rare).

• Mycobacterium tuberculosis. (special form of pneumonia)

2. Chlamydia pneumoniae. (5%)

A form between bacteria & virus.

3. Viral : (5%)

• Influenza & para-influenza.

• Measles & chicken pox.

• Syncytial respiratory virus.

4. Other rare organisms:

• Rickettsia: Coxiella burneti (Q fever).

• Protozoa: Pneumocystis carinii.

• Fungus: Candida, Actinomyces & Aspergillus.

• Parasites: Schistosoma, Ascaris & Ankylostoma.

II.           Non-infective:

1. Chemical: war gasses & lipoid pneumonia.

2. Physical: irradiation.

3. Allergic: Loffler’s syndrome (due to filariasis).

4. Immunological: collagen diseases e.g. SLE.

ANATOMICAL CLASSIFICATION

I. Lobar - pneumonia.

II. Lobular pneumonia (Broncho-pneumonia).

III. Sub-lobular (sub-segmental) pneumonia.

According To The Situation In Which Pneumonia Occurs

I. Community acquired pneumonia (CAP).

II. Hospital acquired pneumonia (Nosocomial pneumonia).

III. Pneumonia in the immune-compromised host.

IV. Aspiration & orthostatic pneumonias.