A 5-year-old boy develops sudden-onset high fever, severe throat pain, and difficulty swallowing. Examination shows a grayish-white membrane firmly adherent to the tonsils that bleeds on attempted removal, with tender cervical lymphadenopathy ('bull neck'). What is the MOST dangerous immediate complication?

• A Peritonsillar abscess
• B Laryngeal obstruction causing respiratory failure ✓
• C Myocarditis
• D Renal failure

Explanation

This is classic diphtheria caused by Corynebacterium diphtheriae. The most immediately life-threatening complication is extension of the pseudomembrane to the larynx and tracheobronchial tree, causing airway obstruction and asphyxia. This is also called 'laryngeal croup' in diphtheria. Myocarditis is a serious delayed complication (1-2 weeks) due to exotoxin effect, but airway obstruction is the immediate emergency requiring urgent airway management plus antitoxin and penicillin.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.