Diphtheria primarily affects which part of the human body?

Raj. CHO -2025

Microbiology

Easy

Appeared in: Raj. CHO -2025

Explanation

Diphtheria is an infection caused by Corynebacterium diphtheriae that primarily targets the mucous membranes of the upper respiratory tract.
The most common site of infection is the throat, including the pharynx and tonsils, where the bacteria multiply.
The hallmark of the disease is the formation of a dense, gray 'pseudomembrane' over the tonsils and pharynx.
This localized infection in the throat can lead to severe complications, most notably airway obstruction from the expanding membrane.

Option B: The stomach is not a site for diphtherial infection. The bacteria primarily colonize the respiratory tract.
Option C: The liver is not the primary site of infection. The bacteria do not multiply in the liver.
Option D: This is a procedural option indicating the test-taker did not answer the question. It is not a medically relevant choice.

Visual 1: Diagram - An anatomical illustration of the upper respiratory tract, highlighting the pharynx and tonsils as the primary sites for diphtherial infection.
Visual 2: Clinical Image - A photograph showing the characteristic gray pseudomembrane covering the tonsils and pharynx in a patient with diphtheria to help visualize the key clinical sign.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Primary site of infection for Diphtheria as background academic context rather than a clinical decision trigger.
The primary nursing concern in a patient with pharyngeal diphtheria is monitoring for and managing airway obstruction. The presence of a pseudomembrane, neck swelling ('bull neck'), and stridor are red flags.
Prevention through vaccination (DPT/DTaP/Tdap) is the most effective measure against diphtheria. Nurses play a crucial role in immunization advocacy and administration.
What if? If a patient presents with a chronic, non-healing skin ulcer with a grayish membrane, especially in a tropical region or an unimmunized individual, the nurse should consider the possibility of cutaneous diphtheria. While less severe systemically, it is still a source of transmission.

How to Approach the Question

First, identify the core subject of the question, which is 'Diphtheria'.
This is a factual recall question. Access your knowledge about the pathophysiology of this specific infectious disease.
Recall the classic symptoms and signs of diphtheria. The most well-known feature is a severe sore throat with a membrane formation.
Evaluate the options based on this key feature. 'Throat' directly corresponds to the location of the pharynx and tonsils, where the characteristic pseudomembrane forms.
Eliminate other organs like the stomach and liver, recognizing they are not the primary sites of this respiratory infection, even if they can be affected by its toxins.

Concept Tested & Keywords

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