Sunday, August 16, 2009

Monoarthritis As A Presenting Feature in Acute Rheumatic Fever

This case report had been presented as a free paper in the 3rd National Scientific Meeting in Emergency Medicine in Kota Kinabalu, Sabah 23rd - 25th April 2009.


Hamizah K, Chew K S
Emergency Medicine Department,
School of Medical Sciences,
Health Campus,
Universiti Sains Malaysia,
16150 Kubang Kerian,
Kelantan, Malaysia


Acute rheumatic fever (ARF) and its chronic sequela, rheumatic heart disease (RHD) are major causes of mortality and morbidity in many Asian countries including Malaysia (1). This is especially so among the low-income families, regardless of ethnicity (2). In a 10-year study done in University Hospital Kuala Lumpur from January 1981 to December 1990, it was found that ARF contributed to 21.2 per 100,000 pediatric admissions per year (2).

In this report, we highlighted the lessons we learned that, unless we maintain a high index of suspicion and perform a thorough cardiovascular examination, otherwise, too strict adherence to the modified, updated Jones criteria may result in a deceitfully wrong diagnosis, a delay in initiating anti-inflammatory treatments and thus, an increased likelihood of ARF to complicate with RHD.

Case Report

A 10-year old boy who was previously well, came to the emergency medicine department of Hospital Universiti Sains Malaysia (HUSM) complaining of a solitary right knee pain and swelling for one-day duration. The joint pain started one day prior to admission; started after he woke up from his sleep. Although aggravated by movement, the pain was not migratory, but rather, confined to the right knee. Nonetheless, he was still able to walk without much of a limping gait and was able to bear his own weight.

He denied any prior history of trauma. Neither did he give a history of similar episode of complaints in the past nor any prior recent episode of upper respiratory tract infection or sore throat.

He did, however, mention that he had history of mild fever started two days earlier before with the onset of the joint pain. Because of the knee pain and fever, he went to a health clinic and was given some paracetamol tablets and a course of antibiotics. His fever subsequently settled but the annoying joint pain and swelling persisted.

On arrival to the emergency department HUSM, the boy was afebrile with normal vital signs. His right knee was warm, mildly swollen and tender over the anterolateral aspect but he was able to walk in the emergency department with a slight limited knee flexion during the swing phase. In fact he was triaged to the Green Zone (non-urgent cases) of the emergency department.

Clinically, he appeared to have an early-onset suppurative arthritis. However, on cardiovascular examination, we found that he had a grade III systolic murmur over the apical area. No other manifestations fulfilling other major Jones criteria. His right knee examination revealed a slightly reduced range of movement to about 120°. Otherwise, no clinical evidence that he had gross joint effusion.

With that, we decided to proceed to investigate the child. The full blood count on admission showed hemoglobin level of 10.2 g/dl, total while cell count of 12,900/mm3 and a platelet count of 548,000/mm3. His admission erythrocyte sedimentation rate (ESR) was noted to be more than 140 mm/hour and his anti-streptolysin O titre (ASOT) was 800 IU/mL.

Blood culture and sensitivity was negative, and renal and liver function tests were within normal range. A right knee x-ray did not show any radiological evidence of septic arthritis and his electrocardiograph (ECG) revealed a sinus tachycardia with normal PR interval. He was admitted to the pediatric ward with a provisional diagnosis of acute rheumatic fever with carditis.

The next day, an echocardiogram was done showing a severe mitral regurgitation with a mild aortic regurgitation and an ejection fraction (EF) of 35%. In pediatric ward, he was then on Penicillin, Aspirin together with Captopril and Frusemide. He was discharged with the continuation of his medications after about ten days of admission in the pediatric ward.

ARF is diagnosed by using the modified and updated Jones criteria (3,4). Nevertheless, one should bear in mind that the current Jones criteria published in 1992 was modified, revised twice and updated from the original Jones criteria first proposed by Dr. T. Duckett Jones in 1944 (3). The reason for the many revisions is to increase the specificity of the criteria in response to the reducing number of ARF cases in developed countries (3).

Unfortunately, the increased specificity has also resulted in decreased sensitivity as a trade-off. For example, the original Jones criteria include arthralgia as a major criterion (3), whereas today, arthralgia is considered as a minor criterion. Migratory polyarthritis, on the other hand, is a classical symptom and a major criterion mentioned in all standard medical textbooks; so much so that in our university, migratory polyarthritis, being such a unique, pertinent feature, has almost become a synonym with ARF among our medical students. Harlan et al found gave a similar observation regarding the emphasis of migratory polyarthritis in standard textbooks (5).

Jones Criteria (1992)
Two major or one major and two minor manifestations must be present, plus evidence of antecedent group A streptococcus infection

Chorea and indolent carditis do not require evidence of antecedent group A streptococcus infection

Major Manifestations:
• Carditis
• Polyarthritis
• Chorea
• Erythema marginatum
• Subcutaneous nodules

Minor Manifestations:
• Arthralgia
• Fever
• Raised Erythrocyte Sedimendation Rate (ESR) or C-reactive Protein (CRP) level
• Prolonged PR interval on electrocardiogram

Evidence of antecedent group A streptococcus infection:
• Positive throat culture or rapid antigen test for group A streptococcus
• Raised or rising streptococcal antibody (ASOT) titre

WHO Criteria (2002-03)
Chorea and indolent carditis do not require evidence of antecedent group A streptococcus infection

First episode
As per Jones criteria

Recurrent episode
In a patient without established RHD, as per first episode

In a patient with established RHD: requires two minor manifestations, plus evidence of antecedent group A streptococcus infection. Evidence of antecedent group A streptococcus infection as per Jones criteria, but with addition of recent scarlet fever

Monoarthritis has been increasingly reported in the literature as a presenting feature in ARF (3,5,6,7). In a study of a population with very high incidence of ARF in Australia, it was found that monoarthritis, rather than polyarthritis, was the presenting feature in up to 17% of the 377 confirmed cases of ARF and 35% of the 216 unconfirmed cases of ARF (described by the researchers as “possible ARF, not satisfying the Jones critera”) (6). More importantly, it was found that 13% of these 216 unconfirmed cases would have satisfied the Jones criteria should monoarthritis was considered as a major criteria6. As such, the World Health Organization in 2002-03 had come out with less stringent criteria, especially for the diagnosis of recurrent ARF in the setting of established RHD (3).

The problem with monoarthritis is that many of these cases mimicked and would have been treated as cases of suppurative arthritis. In a case series reported by Harlan et al, they found that all three cases that eventually found to have ARF were initially treated with antibiotics for suppurative arthritis (5). The cases reported by them had similar presentations to our case. We were fortunate that the cardiac murmur was picked up incidentally during cardiovascular examination.

Another interesting observation found was that many of the cases presented with monoarthritis rather than polyarthritis had been given nonsteroidal anti-inflammatory agents (NSAIDs) either in the community clinics or the emergency medicine department (6,7). In our case, the patient was given paracetamol. Although there had not been scientific study looking into the effects of either NSAIDs or paracetamol toward the joint manifestations in rheumatic fever, NSAIDs use was postulated to have mask the polyarthritis presentation (6), resulting in a milder form of monoarthritis manifestation. In the same way, we believe that the use of paracetamol could have partially resolved the joint inflammation resulting in the milder form of monoarthritis.

Even if the paracetamol had not had an effect over the joint inflammation, it would have very likely resolved his fever. In fact, although fever in ARF is generally defined as an oral or tympanic membrane temperature of 38°C or higher (3), low-grade fever was found to be a common manifestation in high incidence areas (6). In a study done in high incidence area, the number of ARF with fever as a minor criteria 89% if the cut-off point was taken as ≥ 37.5°C and 71% if the cut-off point was taken as ≥38.0°C (6).

Finally, the absence of a recent history of sore throat should never stop us from considering this all-important diagnosis of ARF. In the case series by Harlan et al, only one out of the three cases had a history of recent sore throat (5).


1. Ibrahim A, Rahman AR. Rheumatic heart disease: how big is the problem? Med J Malaysia. 1995 Jun;50(2):121-4.

2. Omar A. Pattern of acute rheumatic fever in a local teaching hospital. Med J Malaysia. 1995 Jun;50(2):125-30.

3. Carapetis JR, McDonald M, Wilson NJ. Acute rheumatic fever. Lancet. 2005 Jul 9-15;366(9480):155-68.

4. Guidelines for the diagnosis of rheumatic fever. Jones Criteria, 1992 update. Special Writing Group of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young of the American Heart Association. JAMA. 1992 Oct 21;268(15):2069-73.

5. Harlan GA, Tani LY, Byington CL. Rheumatic fever presenting as monoarticular arthritis. Pediatr Infect Dis J. 2006 Aug;25(8):743-6.

6. Carapetis JR, Currie BJ. Rheumatic fever in a high incidence population: the importance of monoarthritis and low grade fever. Arch Dis Child. 2001 Sep;85(3):223-7.

7. Wilson E, Wilson N, Voss L et al. Monoarthritis in rheumatic fever? Pediatr Infect Dis J 2007; 26 (4):369-70.

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