Sydenham’s Chorea as the Sole Presenting Symptom of Acute Rheumatic Fever in a 14-Year-Old Boy: A Case Report

Abstract

Background:

Rheumatic chorea is an uncommon but time-honored neurological manifestation of acute rheumatic fever that usually presents weeks to months after an untreated streptococcal pharyngitis. When it presents alone, that is, without other manifestations of the disease, it could easily be overlooked or delayed in its diagnosis. In such a scenario, it is uniquely presented as an isolated primary presentation of rheumatic fever, which underscores the challenge of diagnosis and the importance of early recognition.

Case presentation:

A 14-year-old boy presented with automatic, aimless, and arrhythmic movements of his limbs and face. There was no fever, rash, or joint pain in the preceding weeks. Neurological examination demonstrated choreiform movements typical of Sydenham’s chorea, and serology suggested a recent Group A streptococcal infection. Transthoracic echocardiography revealed mild mitral valve leaflet thickening with mild mitral regurgitation consistent with subclinical rheumatic carditis. The patient was treated with benzathine penicillin for eradication and long-term prophylaxis, and valproic acid for symptomatic control. Symptoms improved over weeks and follow-up assessments showed near resolution of valvular changes without development of clinically significant rheumatic heart disease.

Conclusion:

This case highlights that rheumatic chorea may occur as an isolated type of acute rheumatic fever. Recognition of such a presentation is important in making early diagnosis and treatment, which are essential to prevent long-term effects such as rheumatic heart disease.

Introduction

Acute Rheumatic Fever (ARF) remains a significant cause of acquired heart disease in children and young adults in many parts of the world, despite being preventable. It is an autoimmune response to an untreated or inadequately treated infection with Group A Streptococcus pyogenes, typically affecting the heart, joints, brain, and skin.

The diagnosis is guided by the revised Jones Criteria, which require evidence of a preceding GAS infection along with either 2 major manifestations or 1 major and 2 minor manifestations. The primary criteria are: Carditis, Polyarthritis, Chorea, Erythema Marginatum, and Subcutaneous Nodules.

Rheumatic chorea (RC) is a debilitating neurological presentation of rheumatic fever (RF). RC is characterized by rapid, involuntary, non-rhythmic, and purposeless movements, muscular weakness, and emotional lability. It is often a delayed manifestation, appearing months after the inciting infection when other inflammatory markers have normalized. Its presentation as the first and only sign of ARF is a well-documented but rare clinical scenario that can lead to misdiagnosis or delayed diagnosis.^1,2 Chorea alone has been identified in 0.6% cases of RF in Nepal, and along with carditis, its incidence increased to 2.3%. ³ In Egypt and India, there is no evidence of rheumatic fever presenting as chorea alone. In Pakistan, 16% children with rheumatic carditis developed chorea in the first presentation, and another 4% in recurrent attacks. ² RC remains the most common cause of any choreiform movement in children.

Failure to recognize chorea as a presenting sign of acute RF and subsequent management predisposes the child to recurrent attacks of RF and also rheumatic heart disease. ⁴ We present such a case in a 14-year-old male to highlight this diagnostic pitfall. To our knowledge, this is the first reported case from Egypt describing Sydenham’s chorea as the initial and predominant presentation of acute rheumatic fever.

Case Presentation

A 14-year-old boy was taken to the pediatric neurology clinic by his parents due to a 3-week history of abnormal involuntary movements, which were progressively worsening. The movements were characterized as brief, irregular, and flowing, involving the face, upper limbs, and lower limbs, and were absent during sleep, worsening when the boy was under stress or experiencing emotional excitement. The patient was increasingly having difficulty completing daily activities, including eating, writing, and fastening buttons. School teachers noted that the patient was also experiencing a decline in handwriting quality and difficulty paying attention in class, which prompted the family to seek medical attention. The parents also noted that the boy developed new-onset emotional instability with repeated unexplained laughter and crying spells.

Before the onset of symptoms, he had no history of fever, joint pain, swelling, or rash. His parents did recall him having a “bad sore throat” at least 3 months before the start of abnormal movements, which a local physician diagnosed as viral pharyngitis. No antibiotics were prescribed, and the symptoms spontaneously resolved within a few days. There was no family history of neurological, rheumatic, or autoimmune disease. His past medical and developmental history was unremarkable.

During the examination, the patient presented as alert, oriented, and afebrile with stable vital signs: a heart rate of 82 beats per minute, a respiratory rate of 16, and blood pressure of 110/70 mmHg. There were no rashes, nodules, or joint swelling. The neurological examination revealed continuous, unpredictable choreiform movements in all limbs and facial muscles. Characteristic “milkmaid’s grip” and “spooning” postures were observed on his arms. Muscle tone on examination was mildly decreased, but power was intact (5/5) in all muscle groups. Coordination was impaired due to the chorea, and his gait was unsteady, characterized by erratic, dance-like steps. Speech was mildly dysarthric but without aphasia or frank dysarthria. The cardiovascular examination revealed a soft mid-diastolic murmur best heard at the apex.

The laboratory studies showed a normal complete blood count (WBC 7.2 × 10⁹/l, Hb 13.8 g/dl, platelets 285 × 10⁹/l). The erythrocyte sedimentation rate (ESR) was minimally elevated at 28 mm/hour, while C-reactive protein (CRP) was normal at 0.6 mg/l. There were highly elevated titers of anti-streptolysin O (ASO) at 480 IU/ml (normal <200 IU/ml) and anti-DNase B at 320 U/ml (normal <250 U/ml), showing a recent group A streptococcal infection. Throat culture was negative for group A β-hemolytic streptococcus, as was expected due to the timing of the infection. Antinuclear antibody screen were negative. A comprehensive antiphospholipid antibody panel, including lupus anticoagulant, anticardiolipin, and anti-β2-glycoprotein I antibodies, was negative, making antiphospholipid syndrome an unlikely alternative diagnosis. Serum ceruloplasmin and copper were normal, therefore ruling out Wilson’s disease and autoimmune causes of chorea (Table 1).

Table 1.

Summary of Laboratory, Serologic, and Imaging Findings Supporting the Diagnosis of Acute Rheumatic Fever with Rheumatic Chorea.

Test category	Specific test	Patient’s value	Reference range	Clinical significance/interpretation
Hematology	Complete Blood Count (CBC)
	White Blood Cell Count (WBC)	7.2 × 109/l	4.5-11.0 × 109/l	Normal. Suggests no active acute-phase bacterial infection. Common in chorea, which is a delayed complication.
	Hemoglobin (Hb)	13.8 g/dl	12.0-16.0 g/dl	Normal. No evidence of anemia.
	Platelet Count	285 × 109/l	150-450 × 109/l	Normal.
Acute phase reactants	Erythrocyte Sedimentation Rate (ESR)	28 mm/h	0-15 mm/h	Mildly Elevated. A minor criterion for ARF. Indicates low-grade, chronic inflammation. Often normal or only mildly raised in isolated chorea.
	C-Reactive Protein (CRP)	0.6 mg/l	<5.0 mg/l	Normal. A minor criterion for ARF. Can normalize by the time chorea appears, as the acute systemic inflammation has subsided.
Streptococcal serology	Anti-Streptolysin O Titer (ASO)	480 IU/ml	<200 IU/ml	Significantly Elevated. Provides evidence of a preceding Group A Streptococcal (GAS) infection. A key requirement for diagnosing ARF.
	Anti-DNase B Titer	320 U/ml	<250 U/ml	Elevated. Further serological confirmation of a recent GAS infection. Increases the specificity when combined with ASO.
Microbiology	Throat Culture	No growth of Group A Streptococcus	Negative	Negative. This is expected, as the streptococcal infection preceded the neurological symptoms by several weeks/ months.
Biochemistry & metabolic panel	Comprehensive Metabolic Panel (CMP)
	Sodium, Potassium, Chloride, Bicarbonate	Within Normal Limits	–	Normal. Rules out electrolyte disturbances that could contribute to neurological symptoms.
	Blood Urea Nitrogen (BUN)	12 mg/dl	7-20 mg/dl	Normal.
	Creatinine	0.7 mg/dl	0.5-1.0 mg/dl	Normal.
	Alanine Aminotransferase (ALT)	22 U/l	10-40 U/l	Normal.
	Aspartate Aminotransferase (AST)	25 U/l	15-40 U/l	Normal.
	Albumin	4.2 g/dl	3.5-5.0 g/dl	Normal.
Additional specialized tests	Ceruloplasmin	28 mg/dl	20-60 mg/dl	Normal. Performed to rule out Wilson’s disease, a rare but important differential for chorea in a young person.
	Copper, Serum	95 µg/dl	70-140 µg/dl	Normal.
	Antinuclear Antibody (ANA)	Negative (<1:80)	Negative	Negative. Helps rule out systemic lupus erythematosus (SLE) as a cause of chorea (Lupus-associated chorea).
	Antiphospholipid antibody panel (LA, aCL IgG/IgM, anti-β2-GPI IgG/IgM)	Negative	Negative	Negative. Rules out Antiphospholipid Syndrome.
Imaging & other studies	Echocardiography	Findings: Thickened, mildly restricted mitral valve leaflets with mild mitral regurgitation. Normal ventricular function.	No valvular pathology	Abnormal. This finding is critical. It provides the second major Jones Criterion (Carditis), confirming the diagnosis of ARF, even in the absence of a loud clinical murmur (“subclinical carditis”).
	Brain MRI (with contrast)	No acute abnormalities. Normal signal intensity in basal ganglia. No contrast enhancement.	No structural lesions	Normal. Rules out other causes of chorea such as basal ganglia strokes, tumors, or demyelination. Normal MRI is typical for Rheumatic Chorea.

Bold values indicate abnormal laboratory findings that are clinically relevant to the case presentation.

A brain MRI revealed normal signal intensity and morphology of the basal ganglia, without any ischemic, inflammatory, or demyelinating lesions. Echocardiography showed mild mitral valve regurgitation of thickened mitral leaflets with normal ventricular function, which is consistent with evidence of subclinical rheumatic carditis. Electrocardiography revealed a normal PR interval of 0.11 seconds. According to the revised Jones criteria, the diagnosis of acute rheumatic fever with rheumatic chorea is confirmed by the presence of Sydenham’s chorea as a significant criterion, elevated ESR as a minor criterion, and serological evidence of recent streptococcal infection (Table 1).

The patient was admitted for initiation of therapy. He received a 1-time dosing of benzathine penicillin G (1.2 million units) intramuscularly for primary prevention and will receive long-term secondary prophylaxis every 4 weeks. Valproic acid was initiated on day 1 at a dose of 20 mg/kg/day in divided doses for the treatment of choreiform movements. In our patient, after multidisciplinary review and discussion with the family, we opted not to initiate corticosteroids because the chorea was assessed as mild–moderate, the patient showed prompt symptomatic response to valproic acid, and the family preferred to avoid potential corticosteroid-related adverse effects. Psychological counseling and occupational therapy were initiated for assistance with motor coordination and academic outcomes.

At the 4-week follow-up appointment, the patient showed significant clinical improvement in several key areas: the frequency of the choreiform movements decreased, the intensity decreased, the patient’s handwriting improved, and the patient’s emotional stability returned. A follow-up echocardiogram showed near resolution of the mild thickening of the mitral valve. The patient was advised to continue penicillin prophylaxis monthly, as provided previously, to help prevent reoccurrence of rheumatic fever and potentially rheumatic heart disease.

The patient described initial distress and frustration due to the involuntary movements that interfered with daily activities and school performance. Following diagnosis and initiation of appropriate therapy, he reported gradual improvement in motor control and emotional stability. He expressed understanding of the need for continued prophylaxis and follow-up to prevent recurrence and long-term complications.

Discussion

RC, or Sydenham’s chorea (SC), is a delayed neuropsychiatric sequela of ARF that arises due to autoimmune disease following infection with Group A β-hemolytic streptococcus (GABHS).^5,6 Defined as the onset of abrupt, irregular, involuntary movements of the face, limbs, and trunk; emotional lability; and hypotonia. ⁷ In various developed parts of the world, ARF incidence has decreased; RC remains a major source of morbidity in developing countries where GABHS infections are still widespread. ⁸

RC is one of the major Jones criteria used for the diagnosis of ARF. When it appears as a symptom, it can sometimes be more definitively diagnosed based on a preceding history of streptococcal infection. ⁹ As noted in the present case, it typically appears weeks to months following a sore throat, which suggests the delayed autoimmune process involved in the disease process. ¹⁰ In this case, however, the clinical history of pharyngitis 3 months beforehand, when treated appropriately, with a positive ASO and anti-DNase B titer, was very suggestive of a preceding GABHS infection.

The absence of a clinically detectable murmur in our case masked subtle valvular involvement, which was subsequently identified on echocardiography as mild mitral regurgitation. This finding is recognized as subclinical carditis, which the 2015 Jones criteria include as evidence of rheumatic carditis. Echocardiographic valvulitis (even without audible signs) qualifies as a major ARF manifestation. The international consensus on Sydenham chorea similarly underscores routine cardiac evaluation: pediatric SC guidelines recommend ECG and Doppler echocardiography for all suspected cases, noting that occult valvular disease is common in children with chorea. Recognizing subclinical valve lesions early allows initiation of prophylaxis to prevent progression to overt rheumatic heart disease. The presence of Sydenham’s chorea together with echocardiographic evidence of subclinical carditis therefore fulfills 2 major Jones criteria, definitively confirming the diagnosis of acute rheumatic fever.^11,12

It is thought that the primary mechanism of RC may involve molecular mimicry and result from immunological attacks by antibodies against pathogens in the group A streptococci family directed against streptococcal antigens, which cross-react with neurons primarily in the basal ganglia, resulting in this patient’s dopaminergic deficiency and the development of chorea clinical features. ¹³ This disease process is more prevalent in females and children aged 5 to 15 years; however, there are cases of affected males, which was the case of our patient.^14,15 The emotional lability is a significant neuropsychiatric feature of Sydenham’s chorea and may precede the onset of motor symptoms. ¹⁶

The management of rheumatic fever (RF) includes eradication of streptococcal infection, long-term antibiotic prophylaxis, and symptomatic treatment of chorea. Penicillin is always the drug of choice for primary and secondary prophylaxis. Medications used for symptomatic treatment include valproic acid, carbamazepine, and neuroleptics (ie, haloperidol). ¹⁶ In this case, valproic acid was used due to its favorable safety profile and efficacy in treating generalized choreiform movements. Most patients will remit spontaneously within weeks to months; however, recurrent chorea may occur, especially in non-compliant patients. ¹⁷ It is crucial to identify RC as an early presenting sign of ARF to implement prophylaxis to prevent further episodes and the development of chronic rheumatic heart disease. In endemic countries, when children present to a medical provider for the first time with chorea, the medical provider needs to consider the potential presence of rheumatic fever, regardless of whether fever or arthritis symptoms are present. ¹⁸

For symptom control, anticonvulsants are preferred over older neuroleptics due to better tolerability. The consensus panel notes that agents such as sodium valproate or carbamazepine are useful for chorea, whereas haloperidol or chlorpromazine often produce more side effects. Indeed, our use of valproate aligns with evidence of its efficacy in SC. However, valproate’s teratogenicity demands caution. Recent regulatory advisories (WHO, MHRA) advise against valproate use in women and girls of childbearing age except in strict circumstances. The SC guideline explicitly recommends minimizing valproate dose and duration (typically ⩽600 mg/day, ⩽6 months) if used, and ensuring pregnancy prevention strategies in post-pubertal patients. In practice, this means preferentially using alternatives when possible. For example, carbamazepine or levetiracetam are viable options with a more favorable reproductive safety profile. Second-generation antipsychotics (eg, risperidone) or short-term benzodiazepines can also be considered for girls. In summary, clinicians should balance valproate’s efficacy against its risks: use the lowest effective dose for the shortest time, and consider safer alternatives in females of reproductive potential.^7,12

Expert guidelines favor immunotherapy (corticosteroids) for moderate-to-severe Sydenham chorea. Although our patient improved with valproate alone, recent data show that steroids significantly shorten chorea duration and reduce relapse. In a meta-analysis of 1479 SC patients, those treated with ⩾1 month of corticosteroids had a median chorea duration of ~1.2 versus 2.8 months without steroids. Antibiotics and valproate also lowered relapse risk in that study. Reflecting this, the 2025 consensus guidelines strongly recommend offering corticosteroids to patients with moderate or severe SC. Prednisolone or equivalent is cited as first-line immunotherapy, with IVIG or plasmapheresis reserved for refractory cases. Thus, while valproate addresses symptoms, adding steroids early is now considered best practice to hasten resolution and minimize disease severity.^7,12

Besides motor recovery, one of the larger considerations in Sydenham’s chorea is the risk of chronic and/or latent neuropsychiatric sequelae with obsessive compulsive features, anxiety or attention deficit disorders that can impede quality of life. ¹⁹ The working differential diagnosis should have a reasonable breadth. The appropriate extent of etiologic testing depends on ARF risk in the patient’s setting. Consensus recommendations state that investigations in SC should confirm preceding GAS infection and check for other RF features while tailoring tests to local epidemiology. In practice, this means that in a low-risk region (low ARF prevalence), a new-onset chorea warrants an exhaustive workup for alternative causes (neuroimaging, metabolic and autoimmune screens, etc.). Conversely, in a moderate-to-high–risk area like Egypt, a classic presentation (chorea with streptococcal serologies) allows more focused testing. The SC guidelines explicitly note that in low-risk populations a more thorough diagnostic evaluation is advised, whereas in high-risk populations evaluation can be targeted based on common local differentials. In our case, the workup appropriately emphasized GAS evidence and rheumatic markers, reflecting this risk-adapted strategy. ¹² Wilson’s disease, chorea associated with systemic lupus erythematosus, Huntington’s disease, drug-induced chorea, and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) should be included. From a public health perspective, this is an example of how rheumatic fever can be circumvented through appropriate diagnosis and management of streptococcal pharyngitis (especially in endemic circulation). Most patients fare well on valproic acid or carbamazepine for symptomatic relief. However, those with severe symptoms unresponsive to first-line agents may require a higher level of therapy that may consist of corticosteroids, intravenous immunoglobulin, or plasmapheresis. Treatment is individualized according to where they are along the treatment spectrum.

This case highlights Sydenham’s chorea as the sole presenting manifestation of acute rheumatic fever in an adolescent from an endemic region. A key strength is the comprehensive diagnostic approach, including streptococcal serology and routine Doppler echocardiography, which identified subclinical mitral regurgitation and fulfilled the revised Jones criteria. Early recognition allowed prompt initiation of eradication therapy and secondary prophylaxis, supporting prevention of rheumatic heart disease. The report also demonstrates short-term clinical and echocardiographic improvement with guideline-supported management. However, as a single case report, generalizability is limited. The relatively short follow-up period does not allow assessment of long-term valvular outcomes or relapse risk. Additionally, spontaneous remission of chorea cannot be excluded, and corticosteroid therapy— now recommended in moderate - to - severe cases —was not used. Despite these limitations, the case emphasizes the importance of maintaining high clinical suspicion for rheumatic fever in children presenting with isolated chorea.^6,7,11,12

Conclusion

This case highlights Sydenham’s chorea as a classical but often missed presentation of acute rheumatic fever in children and adolescents. As demonstrated from the case presentation, autoimmune processes may be slow to develop after streptococcal pharyngitis, especially when inadequately treated. Identification of chorea as a major Jones criterion, afforded time to implement antibiotic prophylaxis prior to developing a serious course, such as rheumatic heart disease. Symptomatic management with valproic acid had safe and effective management options for involuntary movements and neuropsychiatric symptoms. Additionally, this case highlights the significance of clinical awareness and public health measures in reducing the burden of rheumatic chorea in developing countries.