Which feature is a hallmark of diphtheria pharyngitis?

Which feature is a hallmark of diphtheria pharyngitis?

• A. Pseudomembranes on the pharynx that bleed if scraped
• B. Koplik spots on the mucosa
• C. Petechial hemorrhages on palate
• D. Vesicular lesions on the lips

Answer: (A)

The key trait being tested is the formation of a gray‑white pseudomembrane that adheres to the pharyngeal mucosa and bleeds when scraped. This membrane is a sheet of necrotic epithelial cells, fibrin, and bacteria produced by Corynebacterium diphtheriae as its toxin damages surrounding tissue. Its friable nature—bleeding on gentle scraping—reflects the underlying necrosis caused by the toxin, and this is a classic clue for diphtheria pharyngitis. Context helps: Koplik spots are characteristic of measles, not diphtheria, and petechiae on the palate or vesicular lips point to other conditions such as viral exanthems or herpes, not the diphtheria membrane. Recognizing the pseudomembrane guides urgent management, which involves antitoxin to neutralize circulating toxin, antibiotics to eradicate the organism, and airway precautions if needed; vaccination with DTaP is the preventive measure.

The key trait being tested is the formation of a gray‑white pseudomembrane that adheres to the pharyngeal mucosa and bleeds when scraped. This membrane is a sheet of necrotic epithelial cells, fibrin, and bacteria produced by Corynebacterium diphtheriae as its toxin damages surrounding tissue. Its friable nature—bleeding on gentle scraping—reflects the underlying necrosis caused by the toxin, and this is a classic clue for diphtheria pharyngitis.

Context helps: Koplik spots are characteristic of measles, not diphtheria, and petechiae on the palate or vesicular lips point to other conditions such as viral exanthems or herpes, not the diphtheria membrane. Recognizing the pseudomembrane guides urgent management, which involves antitoxin to neutralize circulating toxin, antibiotics to eradicate the organism, and airway precautions if needed; vaccination with DTaP is the preventive measure.