Rheumatic fever and rheumatic heart disease

What it is

Rheumatic fever is a post-infectious immune response to Group A Streptococcus (Streptococcus pyogenes). The pathophysiology is molecular mimicry leading to an autoimmune attack on heart, joints, skin and CNS, through a type II hypersensitivity reaction with inflammation and cell damage. The order is fixed: untreated GAS pharyngitis or tonsillitis, then development of antibodies, then a latent period of 2-4 weeks, then the onset of rheumatic fever. Peak incidence is 5-15 years of age. Rheumatic fever develops following an immunological reaction to a recent Streptococcus pyogenes infection, 2-6 weeks ago.

How it presents

The five major criteria are held by JONES, or CASES in the Duckett-Jones form:

1. Joints: migratory polyarthritis
2. Carditis: pancarditis, that is endocarditis, myocarditis and pericarditis
3. Nodules: subcutaneous, painless, firm, over bony prominences
4. Erythema marginatum: a painless ring-shaped rash, transient macular lesions with central clearing usually found on extensor surfaces of proximal extremities and trunk, seen in around 10% of children with rheumatic fever and rare in adults
5. Sydenham's chorea: involuntary movements with jerking, flinching and emotional lability, 1-8 months after the infection, and the last manifestation

Constitutional: high fever, malaise and fatigue.