Pneumonia in a 4 month old
Dr Ira Shah
Medical Sciences Department, Pediatric Oncall, Mumbai, India
Address for Correspondence: Dr Ira Shah, 1, B Saguna, 271, B St Francis Road, Vile Parle {W}, Mumbai 400056, India.
Clinical Problem :
A 4-month-old boy presented with fever, cough, cold since 5 days and breathlessness since 1 day with decreased appetite. He was a full term normal delivery without antenatal or postnatal complications on bottle feeds with cow’s milk. He was immunized till date with OPV, DPT and BCG. On examination, he had respiratory rate of 58, min with intercostals, substernal retractions and was febrile. There were bronchial breath sounds on right infrascapular region. Other systems were normal. Investigations showed:
• Hemoglobin = 10.2 gm, dl
• WBC count = 30,800, cumm {58 percent polymorphs, 42 percent lymphocytes}
• Platelet count = 6,75,000, cumm
• Arterial blood gas = pH = 7.39, PCO2 = 35, mm PO2 = 61, mm of Hg, bicarbonate = 21 mEq, L and oxygen saturation of 91 percent.
• ESR = 115 mm at end of 1 hour
• Chest X-Ray = Bilateral lower zone pneumonia with minimal pleural effusion and inter fissural effusion on right side.
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Which is the organism causing the pneumonia_?
Discussion :
The common organisms causing pneumonia in this age group are:
• Streptococcus pneumoniae
• Hemophilus influenza b {Hib}
• Staphylococcus aureus
• Atypical organisms such as Chlamydia
• Viral pneumonia.
This child has high counts and has bronchopneumonia with effusion. Hence viral pneumonia seems unlikely. The atypical organisms usually cause cough and breathlessness and have crepitations. Also in infants, chlamydia pneumonia is usually seen following neonatal conjunctivitis due to Chlamydia infection. Mycoplasma and ureaplasma are usually seen in school going children. Thus, atypical pneumonias cause more signs of interstitial lung disease rather than lobar pneumonia and also seem unlikely in this child. Among the bacterial infections, Hib is the commonest organisms in this age group and can lead to effusions. Also this child has not received Hib vaccine. Streptococcus pneumoniae leads commonly to lobar pneumonia whereas staphylococcus aureus leads to a rapidly progressive necrotizing pneumonia with deterioration in a matter of hours. Thus most likely cause of pneumonia in this child is a Hib infection. This child’s blood culture grew H influenza b and he responded to ceftriaxone.
E-published: December 2010 Vol 7 Issue 12 Art No. 75
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