The classic exam finding in diphtheria is which of the following?

• A. Papular rash on trunk.
• B. Supraclavicular adenopathy.
• C. Pharyngeal pseudomembranes.
• D. Splenomegaly.

Answer: (C)

In diphtheria, the hallmark finding is a pharyngeal pseudomembrane. This appears as a grayish-white membrane that tightly adheres to the pharynx and tonsillar areas, often extending across the oropharynx. It consists of fibrin, inflammatory cells, and bacteria, and it can bleed if scraped. The toxin produced by Corynebacterium diphtheriae causes local tissue necrosis leading to this membrane, and it can also produce systemic effects like myocarditis and neuropathies if the toxin disseminates. Treating suspected diphtheria requires prompt antitoxin therapy, antibiotics, and airway precautions, along with isolation to prevent spread. Other options—such as a trunk papular rash, supraclavicular adenopathy, or splenomegaly—are not characteristic features of classic diphtheria and point toward different conditions.