Rheumatic Diseases / Acute rheumatic fever (ARF)
Causes and risk factors
The disease is caused by an immunological reaction against the streptococcal-like constituents of human tissue: the antibodies produced to these constituents also react against their own tissues.
In particular, muscle and heart valve structures, joint tissues and some neuronal antigens are involved.
Which are the symptoms?
Clinical manifestations are:
· high body temperature;
· migrating polyarthritis;
· subcutaneous nodules;
· marginal erythema.
There are no symptoms of the disease, but a history of a recent episode of streptococcal pharyngeal infection and certain associations of symptoms make a correct diagnosis.
How is it diagnosed?
Laboratory tests may include an increase in ESR and an increase in anti-streptolysin titre (TAS), which at least doubles over a few weeks. It should be remembered that a limited increase in TAS in the absence of clinical manifestations is not a sign of rheumatic disease.
How is it treated?
β-haemolytic streptococci must be eradicated, the symptoms of acute disease must be treated and relapses, which can eventually cause irreversible changes to the heart valves, must be prevented.
It is treated with:
- anti-inflammatory therapy: NSAIDs (non-steroidal anti-inflammatory drugs) are used to control inflammation. Patients without signs of heart damage do not need steroids;
- antibiotic therapy: when a case of rheumatic disease is diagnosed, even if there is no positive microbiological test for group A streptococcus, treatment with antibiotics to kill the infection (usually penicillin) is recommended;
- relapse prevention: long-term treatment with benzathine penicillin is useful.