Lesson topic №29 Острая ревматическая лихорадка (Rheumatic fever)

Joint aspiration may be needed to exclude other causes of arthritis (eg, infection). The joint fluid is usually cloudy and yellow, with an elevated white blood cell (WBC) count composed primarily of neutrophils; culture is negative. Complement levels are usually normal or slightly decreased, compared with decreased levels in other inflammatory arthritides.

ECG is done during the initial evaluation. Serum cardiac marker levels are obtained; normal cardiac troponin I levels exclude prominent myocardial damage. ECG abnormalities such as PR prolongation do not correlate with other evidence of carditis. Only 35% of children with ARF have a prolonged PR interval; higher-degree heart block may occur but is uncommon. Other ECG abnormalities may be due to pericarditis, enlargement of ventricles or atria, or arrhythmias.

Echocardiography can detect evidence of carditis even in patients without apparent murmurs and is recommended for all patients with confirmed or suspected ARF.

Echocardiography is also used to detect subclinical carditis in patients with apparently isolated Sydenham chorea and to moni tor the status of patients with recurrences of carditis or chronic rheumatic heart disease.

However, not all echocardiographic abnormalities represent rheumatic carditis; isolated trivial valvar regurgitation or trivi al pericardial effusion may be a nonspecific finding.

To maintain specificity, echocardiographic and Doppler results should meet the following criteria (1) for acute rheumatic carditis:

Doppler flow criteria:

Pathologic mitral regurgitation: Must be seen in at least 2 views, and have a jet length ≥ 2 cm in at least 1 view, a peak velocity of

>3 m/second, and a pansystolic jet in at least 1 envelope

Pathologic aortic regurgitation: Must be seen in at least 2 views, and have a jet length ≥ 1 cm in at least 1 view, a peak velocity of

>3 m/second, and a pandiastolic jet in at least 1 envelope

Echocardiographic morphologic criteria:

Pathologic mitral valve morphologic changes include annular dilation, chordal elongation or rupture with flail leaflet, anterior (or less commonly posterior) leaflet tip prolapse, or beading/nodularity of leaflet tips.

Pathologic aortic valve morphologic changes include irregular or focal leaflet thickening, coaptation defect, restricted leaflet motion, or leaflet prolapse.

Chest x-rays are not routinely done but can detect cardiomegaly, a common manifestation of carditis in ARF.

Biopsy of a subcutaneous nodule can aid in early diagnosis, especially when other major clinical manifestations are absent.

ESR and serum CRP are sensitive but not specific.

The ESR is typically > 60 mm/hour.

CRP is typically > 30 mg/L (> 285.7 nmol/L) and often > 70 mg/L (> 666.7 nmol/L);

because it rises and falls faster than ESR, a normal CRP may confirm that inflammation is resolving in a patient with prolonged ESR elevation after acute symptoms have subsided.

In the absence of carditis, ESR usually returns to normal within 3 months.

Evidence of acute inflammation, including ESR, usually subsides within 5 months in uncomplicated carditis.

The WBC count reaches 12,000 to 20,000/mcL (12 to 20 × 109/L) and may go higher with corticosteroid therapy.

The differential diagnosis includes JIA (especially systemic JIA and, less so, polyarticular JIA), Lyme disease, reactive arthritis, arthropathy of sickle cell disease, leukemia or other cancer, systemic lupus erythematosus, embolic bacterial endocarditis, serum sickness, Kawasaki disease, drug reactions, and gonococcal arthritis.

These are frequently distinguished by history or specific laboratory tests.

The absence of an antecedent GAS infection, the diurnal variation of the fever, evanescent rash, and prolonged symptomatic joint inflammation usually distinguish systemic JIA from ARF.

Modified Jones Criteria for a First Episode of Acute Rheumatic Fever (ARF)*

Prognosis for Rheumatic Fever

Prognosis following an initial episode of acute rheumatic fever depends mostly on how severely the heart is affected, and whether there is a recurrent episode of acute rheumatic fever. Murmurs eventually disappear in about half of patients whose acute episodes were manifested by mild carditis without major cardiac enlargement or decompensation. However, many others develop chronic valvula r disease, including some who recovered from the acute episode without evidence of valvular disease.

Episodes of Sydenham chorea usually last several months and resolve completely in most patients, but about one third of patie nts have recurrences.

Joint inflammation may take 1 month to subside if not treated but does not lead to residual damage.

In patients with chronic valvular disease, symptoms develop and progress slowly, typically over several decades. However, once significant symptoms develop, intervention is usually necessary. In developing countries, chronic rheumatic heart disease is the cause of 25 to 45% of all cardiovascular disease.

Antibiotic treatment

Although poststreptococcal inflammation is well developed by the time ARF is detected, a 10-day course of oral penicillin or amoxicillin, or a single injection of benzathine penicillin, is used to eradicate any lingering organisms and prevent reinfection.

Aspirin and other anti-inflammatory drugs

Aspirin controls fever and pain and should be given to all patients with arthritis and/or mild carditis. Although aspirin has been used for many decades, there are surprisingly few data from controlled trials to define the optimal dosing schedule. Most experts would give children and adolescents 15 to 25 mg/kg orally 4 times a day (to a maximum daily dose of 4 to 6 g) for 2 to 4 weeks and then taper the dose over another 4 weeks. Symptomatic ARF responds dramatically to aspirin. If no improvement is seen after 24 to 48 hours of highdose aspirin therapy, the diagnosis of ARF should be reconsidered. Salicylate toxicity is the limiting factor to aspirintherapy and is manifested by tinnitus, headache, or hyperpnea; it may not appear until after 1 week of therapy. Salicylate levels are measured only to manage toxicity. Enteric-coated, buffered, or complex salicylate molecules provide no advantage.

For patients with minimal to mild carditis, there are no controlled data to suggest that adding prednisone to aspirin therapy speeds resolution of illness or prevents rheumatic heart disease.

Other nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported in small trials to be effective; naproxen (7.5 to 10 mg/kg orally 2 times a day) is the most studied. However, other NSAIDs have few advantages over aspirin, especially in the first week of therapy when salicylism is uncommon. Acetaminophen is not effective for symptoms of acute rheumatic fever.