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Dr Ira Shah
M.D, DCH(Gold Medalist), FCPS, DNB
Pneumonia is infection of the lungs. Other lower respiratory tract
infections seen in children are croup (laryngotracheobronchitis),
bronchitis, and bronchiolitis.
Pneumonia results from direct inflammation of the lung tissue. Most
commonly, it is the result of infections (bacterial, viral or fungal),
but it can occur as a result of chemical injury (gastric acid/ aspiration
of food/ hydrocarbon and lipoid pneumonia/ radiation induced pneumonia).
The causative agent may reach the lung via the blood stream or from
direct inhalation.
The incidence of pneumonia in developing countries in children less
than 5 years old is almost 30% with a high mortality rate.
Clinical features:
Neonates:
Refusal of feeds, lethargy.
Tachypnea, grunting, retractions, cyanosis.
Infants:
Cough, fever, Refusal of
feeds, lethargy.
Tachypnea, grunting, retractions, cyanosis, wheezing, noisy breathing.
Preschoolers:
cough, post tussive vomiting,
fever, chest pain, abdominal pain.
In severe cases: Tachypnea, grunting, retractions, cyanosis,
Older Children:
fever, cough, chest pain,
dysnea. Pharyngitis and otalgia/otitis are other common symptoms.
The pathognomic sign of pneumonia is the presence of crackles
(also called as crepitations). Localized crepts in a febrile child
without underlying lung disease is pneumonia until proven otherwise.
However, not all children with pneumonia have crepitations. Decreased
breath sounds with dull note on percussion and presence of bronchial
breathing are also suggestive of pneumonia.
Common causes of pneumonia:
Newborns:
group B Streptococcus
(GBS), respiratory syncytial virus (RSV).
Infants:
Viruses:
parainfluenza viruses, influenza virus, adenovirus, and respiratory
syncytial virus (RSV). cytomegalovirus
Atypical organisms:
Chlamydia trachomatis, Ureaplasma urealyticum, and Pneumocystis
carinii (PCP). PCP is especially seen in children with immunodeficiencies.
Bacterial: B.
pertussis,
Streptococcus pneumoniae,
Haemophilus influenzae, Haemophilus
influenzae, mycobaterial tuberculosis.
Young children:
Viruses:
parainfluenza viruses, influenza
virus, adenovirus, and respiratory syncytial virus (RSV).
Atypical organisms:
Mycoplasma pneumoniae.
Bacterial:
Pneumococcus, mycobaterial tuberculosis.
Older children and adolescents:
Atypical organisms:
Mycoplasma pneumoniae, Chlamydia
trachomatis.
Bacterial:
Pneumococcus, B. pertussis,
mycobaterial tuberculosis.
Other rare
causes of pneumonia:
- Histoplasma
capsulatum: It
is found in nitrate rich soil from bird droppings and decaying
wood. It is usually acquired as a result of inhalation of spores.
The infection is usually asymptomatic; however, in infants and
young children it may cause respiratory distress and hypoxemia.
- Cryptococcus
neoformans is a common
among pigeon breeders, seen in immunocompromised patients.
- In older children, pneumonia
may complicate common varicella
infections.
Diagnosis of pneumonia:
- Complete
blood count:
WBC count is often increased with
a polymorphic predominance in bacterial infections. Lymphocytic
predominance may be seen in viral pneumonias, pertussis and
atypical infections.
- Cultures:
In the cooperative
older child with a productive cough, a sputum Gram stain is
useful. Sputum cultures and immunofluorescent antibody testing
may be useful. Bactec cultures (sputum or blood) are useful
to isolate the organisms).
- Imaging
Studies: Chest
x-ray PA view is the diagnostic test for pneumonias. Sometimes
to differentiate from a sine-pneumonic effusion, a USG chest
may be required. In rare cases of children who have an effusion
or an empyema identified on CXR, a CT scan may be needed to
further define the scope of the problem.
- Mantoux
Test: To
diagnose pneumonia due to mycobaterial tuberculosis.
- Cold agglutinin
test: A bedside cold
agglutinins test may help confirm the clinical suspicion of
mycoplasmal infection. This test is performed by placing a small
amount of blood in a specimen tube containing anticoagulant
and inserting this into a cup filled with ice water. After a
few minutes in the cold water the tube is held up to the light,
tilted slightly, and slowly rotated. Small clumps of red blood
cells coating the tube are indicative of a positive test result.
This test is positive only in about one half of the cases of
mycoplasmal infection and has high chances of false positive
reactions.
- Other tests:
If there is presence
of pleural fluid, pleural fluid aspiration and culture and microscopy.
Differentiation between bacterial and viral pneumonia:
Bacterial pneumonia:
Usually associated with
a fever more than 103 degree F. It is often a lobar, segmental or
rounded well-defined pneumonia affecting a single lobe or multiple
lobes. There may associated pleural effusion with abscess, bullae
or pneumatoceles.
Viral pneumonia:
The fever is usually lower than 103 degree F. The pneumonia is poorly
defined, interstitial or peribronchial affecting multiple sites predominantly
in multiple sites and poorly defined. There may be subsegmental atelectasis.
Treatment of pneumonia:
- Oxygen is required if there
is grunting, flaring, severe tachypnea, and retractions.
- Bacterial
Pneumonia:
Antibiotics:
oral or intravenous
:
Penicillins: They are
appropriate first-line agents in children in whom pneumococcal
disease is strongly suspected. They have limited activity against
gram-negative bacteria due to resistance.
- Amoxicillin: 40 mg/kg/day PO divided tid/ 100 mg/kg/day IV
qds
- Penicillin V: 40 mg/kg/d PO divided qid
- Crystalline Penicillin: 1,00,000 units/kg/day IV in 6 divided
doses.
- Ampicillin/sublactum: 40mg/kg/day PO divided tid, 100 mg/kg/day
IV qds
- Amoxicillin/clavulanic acid: 40mg/kg/day PO divided tid, 100
mg/kg/day IV qds
Cephalosporins:
First generation
cephalosporins: They are
useful against gram positive organisms and Proteus
mirabilis, H influenzae, Escherichia coli, Klebsiella pneumoniae,
and Moraxella
catarrhalis.
- Cephalexin: 50 mg/kg/day PO bid
- Cefadur : 30-50 mg/kg/day PO bid.
- Cefuroxime: 30 mg/kg/d PO bid, IV: 150-200 mg/kg/d IV divided
q8h.
- Cefalothin: 50 mg/kg/day PO qds / 100 mg/kg/day IV qds.
Second generation
cephalosporin: They are
useful against gram positive organisms and have limited activity
against gram negative organisms.
- Cefaclor: 20-40 mg/kg/day PO tds.
Third generation
cephalosporins: They are
broad-spectrum antibiotics having good gram-negative activity.
- Cefixime: 8 mg/kg/day PO bid.
- Ceftriaxone: 50-100 mg/kg/d IV/IM bd not to exceed 1 g.
- Cefotaxime: 100-200 mg/kg/d IV/IM divided q6-8h.
- Cefpodoxime: 10 mg/kg/d PO divided bid
- Cefprozil: 30 mg/kg/d PO divided bid
Chloramphenicol:
It is a bacteriostastic
drug having good gram positive and gram negative coverage. It
is given along with penicillin and is especially useful in patients
with H. influenza infections. Dose: 100mg/kg/day IV/IM.
Septran :
21 mg/kg/day PO/IV
for 21 days. Useful for PCP pneumonia.
Macrolides:
They are used for treatment
of staphylococcal and streptococcal infections. Also used in
the treatment of atypical pneumonias due to mycoplasma, chlamydias.
- Erythromycin: 30-50 mg/kg/d PO divided q6-8h.
- Clarithromycin: 15 mg/kg/d PO divided q12h.
- Azithromycin: Day 1: 10 mg/kg PO once; not to exceed 500 mg/d
Days 2-5: 5 mg/kg PO qd; not to exceed 250 mg/d.
Vancomycin
is used in children with penicillin resistant streptococci and
methicillin resistant staphylococci. Dose: 45-50 mg/kg/day IV
qds
- RSV: Serious infections with
this organism usually occur in infants with underlying lung
disease. Aerosolized ribavirin can be given to severely affected
infants.
- Herpes virus: Acyclovir is
available for treatment of these pneumonias. Dose: 10 mg/kg/dose
IV q8h; infuse over 1 h
- Influenza A pneumonia, which
is particularly severe or when it occurs in a high-risk patient,
may be treated with amantadine.
- Children who are toxic: Antibiotic
therapy should include vancomycin (particularly in areas where
penicillin resistant streptococci have been identified) and
a cephalosporin.
Sequelae:
- Most children with uncomplicated
pneumonia recover without sequelae. Persistent effusions and
empyemas are the most common serious complications of bacterial
pneumonia.
- Pulmonary abscess
- Respiratory distress
- Sepsis
- Pneumatoceles especially with
staphylococcal infections
- In children who have recurrent
or chronic symptoms, further testing including skin testing
to identify fungal pathogens, sweat chloride estimation to identify
cystic fibrosis, titers against rare organisms, and bronchoscopy
may be required.
Prevention:
Several vaccines exist
that may prevent certain types of pneumonia.
o
Pneumococcal vaccine
should be given to children with asplenia or sickle cell disease
or have undergone splenectomy. A new conjugated pneumococcal
vaccine has been developed and is recommended as a part of the
routine childhood immunization schedule.
o Conjugated
Haemophilus influenzae type B vaccine
is recommended as a part of the routine childhood immunization
schedule and has reduced the incidence of infections caused
by this organism.
o Varicella
vaccine is especially
recommended in children who are immunocompromised or adults
who are unprotected.
o Influenza
vaccines usually are
given only to chronically ill children.
Prognosis:
- The prognosis for most forms
of pneumonia is excellent.
- Most cases of viral pneumonia
resolve without treatment; common bacterial pathogens and atypical
organisms respond to antimicrobial therapy.
- The prognosis for varicella
pneumonia is somewhat more guarded.
- Staphylococcal pneumonia, although
rare, can be very serious despite treatment.
- Immunocompromised children,
those with underlying lung disease, and neonates are at high
risk for severe sequelae.
- Some forms of viral pneumonia,
particularly adenoviral disease, tend to cause bronchiolitis
obliterans and hyperlucent lung syndrome.
Last created on 24-07-2002
Last updated on 01-07-2006
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