**Question:** All the following are major criteria for diagnosis of rheumatic fever (RF) except

A. Heart involvement (rheumatic heart disease)
B. Central nervous system involvement (encephalitis, meningitis)
C. Joint involvement (arthritis)
D. Skin involvement (erythema marginatum)

**Core Concept:**
Rheumatic fever (RF) is a post-infectious complication of group A streptococcal (GAS) pharyngitis that can lead to organ damage, primarily affecting the heart, joints, brain, and skin. The diagnosis of RF requires the presence of at least two major criteria or one major criterion and two minor criteria.

**Why the Correct Answer is Right:**
Option D, "Skin involvement (erythema marginatum)", is not a major criterion for the diagnosis of rheumatic fever. Major criteria for RF include:

1. Heart involvement (rheumatic heart disease): This is a significant criterion as it is the most common manifestation of RF and can lead to significant morbidity and mortality.
2. Central nervous system involvement (encephalitis, meningitis): This criterion involves inflammation of the brain and meninges, respectively, and is present in about 20%-30% of RF cases.
3. Joint involvement: Arthritis is a significant criterion as it is common in RF patients, affecting up to 80% of cases.

**Why Each Wrong Option is Incorrect:**
A. Central nervous system involvement (encephalitis, meningitis): While this criterion is present in some RF patients, it is not a major criterion as it is not present in all cases.
B. Heart involvement (rheumatic heart disease): This is a significant criterion as it is the most common manifestation of RF and can lead to significant morbidity and mortality.
C. Joint involvement (arthritis): This criterion is significant as it is common in RF patients, affecting up to 80% of cases.

**Core Concept:**
Rheumatic fever is a post-infectious complication of group A streptococcal pharyngitis, resulting in inflammation and damage to various organs, particularly the heart, joints, brain, and skin. The diagnosis of RF is based on the presence of at least two major criteria or one major criterion and two minor criteria.

**Why Each Wrong Option is Incorrect:**
A. Heart involvement (rheumatic heart disease): While this is a significant manifestation of RF, it is not a major criterion as it is not present in all cases.
B. Joint involvement (arthritis): This criterion is a major criterion as it is common in RF patients, affecting up to 80% of cases.
C. Joint involvement (arthritis): This criterion is a significant criterion as it is common in RF patients, affecting up to 80% of cases.

**Clinical Pearl:**
A rheumatic fever diagnosis requires the presence of at least two major criteria or one major criterion and two minor criteria. The correct answer is D (joint involvement) because it is a major criterion for the diagnosis of rheumatic fever and is present in approximately 80% of cases.

**Why Each W