DEMOGRAPHICS Pneumonia is the leading infectious cause of death in

children worldwide, accounting for 15% of all deaths of children under 5 years old.

Pneumonia killed an estimated 9,35,000 children under the age of five in 2013.

Pneumonia caused by bacteria can be treated with antibiotics, but only one third of children with pneumonia receive the antibiotics they need.

PNEUMONIA

Pneumonia is a breathing (respiratory) condition in which there is an infection of the lung.

The lungs are made up of small sacs called alveoli, which fill with air when a healthy person breathes.

When an individual has pneumonia, the alveoli are filled with pus and fluid, which makes breathing painful and limits oxygen intake.

CAUSES Streptococcus pneumoniae Haemophilus influenzae type b (Hib) Pneumocystis jiroveci  (in infants infected with HIV)

COMMON SYMPTOMS

Shaking chills Fever Dry cough Muscle aches Nausea/vomiting Rapid breathing Rapid heartbeat Difficulty breathing Chest pain

CLASSIFICATION OF PNEUMONIALOBAR PNEUMONIA

Occurs due to acute bacterial infection of part of a lobe or complete lobe.

Commonly Streptococcus pneumoniae, Staphylococcus aureus and less commonly Haemophilus influenzae, Klebsiella pneumoniae are responsible

BRONCHOPNEUMONIA Acute bacterial infection of the terminal bronchioles

characterized by purulent exudates. Extends into surrounding alveoli through endobronchial

route resulting into patchy consolidation. Commonly Streptococci, Staphylococcus aureus,

Haemophilus influenzae, Klebsiella pneumonia and Pseudomonas are responsible

INTERSTITIAL PNEUMONIA Patchy inflammatory changes Mostly confined to the interstitial tissue of the lung

without alveolar exudates. Characterised by alveolar septal oedema and

mononuclear infiltrates. Commonly Mycoplasma pneumoniae, Respiratory

syncytial virus, Influenza virus, adenoviruses, and uncommonly Chlamydia and Coxiella are responsible

PATHOLOGICAL STAGES OF LOBAR PNEUMONIA

A. STAGE OF CONGESTION

Represents early acute inflammatory response. Affected lobe becomes red and heavy due to vascular

congestion. Proteinaceous fluid, abundant neutrophils and many

bacteria can be seen in the alveoli. Lasts for 1 to 2 days.

B. STAGE OF RED HEPATISATION

Affected lobe becomes red, firm and acquires liver like consistency.

Proteinaceous fluid transforms into fibrin strands with marked cellular exudates of neutrophils.

Extravasation of red cells which give red colour to consolidated lung.

Lasts for 2 to 4 days.

C. STAGE OF GRAY HEPATISATION

Affected lobe becomes dry, firm and gray due to lysed red cells.

Neutrophilic cellular exudates decreases due to breakdown of inflammatory cells and macrophages are now seen.

Micro organism load also reduces. Lasts for 4 to 7 days.

D. STAGE OF RESOLUTION Due to enzymatic action, fibrinous matter is liquefied

and the lung aeration is re-establish gradually. Macrophages are the major cells in the alveoli. There is progressive reduction of fluid and cellular

exudates from the alveoli by way of expectoration and lymphatic drainage leading to normal lung parenchyma in over 3 weeks.

http://www.slideshare.net/vmshashi/pathology-of-pneumonia

LOBAR PNEUMONIA Etiology Staphylococcal pneumonia: Staphylococcus aureus Streptococcal pneumonia: β-haemolytic streptococci Pneumonia by gram-negative aerobic bacteria:

Haemophilus influenzae, Klebsiella pneumoniae Pneumococcal pneumonia: caused by Streptococcus

pneumoniae

CLINICAL FEATURES Shaking, Chills Fever malaise with pleuritic chest pain Dyspnoea Cough with expectoration. The common physical findings are fever, tachycardia and

sometimes cyanosis if the patient is severely hypoxaemic.

BRONCHOPNEUMONIA Etiology Staphylococci Streptococci Pneumococci Haemophilus influenzae Klebsiella pneumonia gram-negative bacilli like Pseudomonas and coloniform

bacteria.

CLINICAL FEATURES Chronic debility Aspiration of gastric contents or upper respiratory

infection Neutrophillic leukocytosis.

INTERSTITIAL PNEUMONIA Etiology Respiratory syncytial virus (RSV) Mycoplasma pneumonia Influenza and parainfluenza viruses, adenoviruses,

rhinoviruses, coxsackieviruses and cytomegaloviruses (CMV).

Occasionally, psittacosis (Chlamydia) and Q fever (Coxiella) are also associated

CLINICAL FEATURES

Fever Headache and muscle aches A few days later appears dry, hacking, non-productive

cough with retrosternal burning Neutrophilic leukocytosis