Elevated levels of antistreptolysin O are seen in:

AIIMS BHOPAL NO- 2018( Shift-2nd)

Medical & Surgical Nursing

Easy

Appeared in: AIIMS BHOPAL NO- 2018( Shift-2nd)

Explanation

Rheumatic fever is an inflammatory disease that develops as a delayed, non-suppurative complication of a pharyngeal infection with Group A Streptococcus (GAS).
The body produces antibodies against toxins produced by GAS, such as streptolysin O. An elevated Antistreptolysin O (ASO) titer is evidence of a preceding streptococcal infection.
According to the Jones Criteria for diagnosing acute rheumatic fever, evidence of a recent GAS infection (such as an elevated ASO titer) is an essential requirement.
ASO titers typically rise 1-3 weeks after infection, peak at 3-5 weeks, and can remain elevated for several months, making them a useful marker for diagnosis.

Option A: Subacute endocarditis is an infection of the heart's endocardium, but it is typically caused by bacteria like Streptococcus viridans or staphylococci, not Group A Streptococcus. Diagnosis relies on blood cultures, not ASO titers.
Option B: A ventricular septal defect (VSD) is a congenital heart defect, which is a structural abnormality present from birth. It is not an infectious or inflammatory condition and has no association with streptococcal infections or ASO levels.
Option D: Cardiomyopathy is a broad term for diseases of the heart muscle. While untreated rheumatic fever can lead to rheumatic carditis (a form of cardiomyopathy), the term itself is not specific. Many other conditions (viral infections, genetic factors, alcohol) can cause cardiomyopathy, and it is not primarily diagnosed using an ASO titer.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Diagnostic markers for Rheumatic Fever as background academic context rather than a clinical decision trigger.
A key nursing role is educating patients and families on the importance of completing the full course of antibiotics for strep throat to prevent severe complications like rheumatic fever and subsequent rheumatic heart disease.
Nurses are responsible for collecting throat swabs for culture and administering antibiotics as prescribed. They also monitor patients with rheumatic fever for signs of carditis, such as new murmurs, tachycardia, or heart failure.
What if? If a patient has a high ASO titer but no clinical signs of rheumatic fever (like carditis or arthritis), it indicates a recent streptococcal infection but not necessarily active rheumatic fever. This patient may be considered a carrier or have post-streptococcal reactive arthritis. Management would focus on ensuring the eradication of strep and monitoring for any developing symptoms, with long-term prophylaxis considered in high-risk cases.

How to Approach the Question

First, identify the core term in the question: 'Antistreptolysin O' (ASO).
Recall or deduce the significance of ASO. The prefix 'anti-' suggests it's an antibody, and 'strepto-' points to a streptococcal infection.
Connect the ASO test to its primary clinical use: diagnosing sequelae of Group A Streptococcus infections.
Evaluate the options: Which condition is a known complication of a streptococcal infection?
Eliminate options that are unrelated: Ventricular septal defect is congenital, and subacute endocarditis has different causative organisms. Cardiomyopathy is too general.
Conclude that Rheumatic fever is the classic post-streptococcal inflammatory disease for which an ASO titer is a key diagnostic criterion.

Concept Tested & Keywords

QyqXPzy5wUQ9OjG21FA8E_

E6 Ghai Essential Pediatrics(pp 26-904 of 913) pp. 460-462, 466-468

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 1717-1719