Minor Manifestations:

Clinical manifestations -

Fever - It is usually present during first week to ten days of rheumatic fever and is rarely above 39 0 C. If patient's temperature elevation persistently exceeds 39 0 C, other cause should be sought. In particular, in the presence of rheumatic heart disease superimposed infective endocarditis should be the first consideration.

Arthralgia - Arthralgia is an extremely common complaint in rheumatic fever. It commonly precedes an acute attack of carditis.

Laboratory minor manifestations -
Laboratory data which can be helpful in the diagnosis of acute rheumatic fever are of two kinds :

• Evidence of Streptococcal infection and
  
  
• Tests for the presence of rheumatic activity.
  
  

• A positive throat culture for group A b-hemolytic Streptococcus . Although old literature quotes throat culture to be positive in 25%, with the common use of antibiotics in almost every febrile child this figure is nowadays hardly ever attained.
  
  
• The most useful and practical test for detecting a preceding streptococcal infection is a rise in antistreptolysinO titre . The rise occurs in a week, reaches a peak in 3-5 weeks and subsides in 2-6 months. It can be detected in about 80% of cases of acute rheumatic fever because it remains elevated far longer than other signs.
  
  

• Erythrocyte sedimentation rate

The elevation of ESR is due to increase in plasma fibrinogen secondary to inflammation. The magnitude of elevation of ESR is often directly proportional to the severity of the disease except in patients with heart failure whose liver may not produce enough fibrinogen.

Elevation of ESR is fairly good index of rheumatic activity. ESR remains elevated for about 4-8 weeks and it may remain high in severe carditis. Also, it may remain high longer in presence of anemia.

ESR is useful in deciding how long a child should remain in bed or when to modify suppressive therapy.

• C-reactive protein

It is not usually present in blood. It appears promptly in the course of any inflammatory reaction. It becomes normal much more readily than ESR and is a helpful adjunct in proving rheumatic activity because of its transient nature and rapid disappearance from blood. ESR is preferable to CRP especially for the follow up of rheumatic activity. CRP is not influenced by anemia or CHF so in the presence of other criteria and normal ESR, CRP is a good indication of rheumatic process. But in the absence of other criteria, normal ESR and elevated CRP suggest non-rheumatic etiology.

• Leukocyte changes are of little help in rheumatic fever due to its variability.
  
  
• Electrocardiogram in rheumatic fever

The most characteristic feature in acute rheumatic fever is conduction disturbances most commonly in the form of 1st degree heart block (a prolonged PR interval) which occurs in 24 - 40%. Dr. Jones in 1944 recommended repeat tracings to demonstrate a variation in atrioventricular conduction which is more valuable. The PR interval usually returns to normal after the disease becomes inactive and it can occur with or without carditis. In acute rheumatic pericarditis, ST elevation or inversion is present.