In a patient with rheumatic fever who presents with abnormal movements, what is the diagnosis and recommended management?

Sydenham Chorea: The Neurological Manifestation of Rheumatic Fever

Abnormal movements in rheumatic fever represent Sydenham chorea (SC), a major diagnostic criterion of acute rheumatic fever (ARF) characterized by rapid, involuntary, nonpatterned choreiform movements, hypotonia, and neurobehavioral symptoms requiring immediate antibiotic treatment and immunotherapy for moderate-to-severe cases 1.

Clinical Recognition

The key diagnostic features you must identify include:

• Choreiform movements: Rapid, unpredictable, involuntary contractions predominantly affecting distal limbs 1, 2
• Milkmaid's grip: Inability to maintain tetanic hand contraction (alternating squeeze-release pattern) 2
• Hypotonia: A cardinal sign alongside chorea 1
• Motor impairments: Unsteady gait, difficulty with fine motor tasks 2
• Neurobehavioral symptoms: Screen for behavioral changes, cognitive impairments 1

Critical pitfall: SC can present as the sole manifestation of ARF without arthritis or obvious carditis 2. Always screen for subclinical carditis with echocardiography, as 50-65% of patients develop cardiac involvement 2.

Diagnostic Workup

The etiological evaluation differs by ARF risk in your population 1:

Laboratory confirmation:

• Anti-Streptolysin O (ASO) titre elevation 2
• Elevated erythrocyte sedimentation rate (ESR) or C-reactive protein 2
• Evidence of recent Group A streptococcal infection 3

Cardiac assessment:

• Echocardiography is mandatory to detect clinical or subclinical carditis 1, 2
• ECG for conduction abnormalities (though complete AV block is rare) 4

Additional screening:

• Assess swallowing and speech function 1
• Evaluate mobility and academic/social functioning 1

Treatment Algorithm

Immediate Management

1. Antibiotic therapy at first presentation 1:

• Initiate antibiotics immediately upon diagnosis
• This addresses the underlying streptococcal trigger

2. Long-term secondary prophylaxis 1:

• Follow international or local guidelines for duration
• Use measures to reduce pain/distress from intramuscular injections to improve adherence
• Critical: Compliance with prophylaxis is essential to prevent cardiac complications 2

Immunotherapy Decision Tree

For moderate-to-severe SC 1:

• First-line: Corticosteroids are recommended
• This represents the most recent (2025) high-quality guideline consensus

For inadequate recovery 1:

• Second-line: Intravenous immunoglobulin (IVIG) OR plasma exchange
• Consider these when corticosteroid response is insufficient

Symptomatic Treatment

For chorea interfering with daily activities 2, 5:

• Antiepileptics, neuroleptics, or phenothiazines may be needed
• Continue therapy for 2-3 weeks after clinical improvement 5
• Note: While older literature 6 suggested chorea was self-limited, current consensus 1 recognizes the need for more aggressive treatment in moderate-to-severe cases

Relapse Management

If SC recurs 1:

• Repeat full clinical assessment
• Repeat etiological investigation
• Reinitiate antibiotics PLUS corticosteroid therapy

Important caveat 3: In patients adherent to prophylaxis with recurrent joint symptoms but lacking serological evidence of streptococcal infection and echocardiographic valvulitis, the symptoms are likely not ARF-related.

Support and Follow-up

Provide comprehensive support to 1:

• Patients and families with information about the condition
• Educators to minimize impact on academic and social functioning
• Address the psychosocial burden of this movement disorder

The distinction from other movement disorders and psychiatric conditions is essential 2, as SC remains a major but potentially overlooked manifestation of ARF, particularly in populations where ARF incidence has declined but not disappeared 7, 8.