A 6-week-old infant presents with repeated bouts of coughing in rapid succession without preceding inspiratory whoop, nasal congestion, and no fever. Chest X-ray shows diffuse interstitial infiltrates, and peripheral smear reveals eosinophilia. The mother had untreated cervical discharge during pregnancy. First-line treatment is:

• A Oral amoxicillin for 10 days
• B Oral cotrimoxazole for 5 days
• C Intravenous ceftriaxone and azithromycin
• D Oral erythromycin for 14 days ✓

Explanation

The afebrile staccato cough, interstitial pneumonitis, and eosinophilia in an infant under 3 months are classic for Chlamydia trachomatis pneumonia acquired from the maternal birth canal. Treatment is oral erythromycin (or azithromycin) for about 14 days. Amoxicillin is wrong because beta-lactams have no activity against Chlamydia, which lacks a peptidoglycan cell wall. Cotrimoxazole is avoided in young infants.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.