Discussion

This case highlights an unusual presentation of acute rheumatic fever characterised by the simultaneous occurrence of three major Jones manifestations—migratory polyarthritis, erythema marginatum, and subcutaneous nodules—in the complete absence of clinical, electrocardiographic, or echocardiographic evidence of carditis. Erythema marginatum and subcutaneous nodules are uncommon manifestations of acute rheumatic fever and have long been recognised to occur in association with carditis. ^{Reference Gewitz, Baltimore and Tani1–Reference Dougherty, Nascimento, Carapetis, Dougherty, Carapetis, Zühlke and Wilson3} The 2015 Jones criteria revision notes that subcutaneous nodules are more frequently observed in patients with carditis and that erythema marginatum and nodules rarely occur as isolated manifestations. ^{Reference Gewitz, Baltimore and Tani1} Against this background, the coexistence of these two cutaneous major manifestations in a patient with persistently normal cardiac evaluation represents an uncommon clinical phenotype.

The well-recognised association between subcutaneous nodules and carditis makes the present case particularly noteworthy. Major reference texts consistently describe subcutaneous nodules as typically accompanying significant cardiac involvement. ^{Reference Lennon, Webb, Cherry, Kaplan, Demmler-Harrison, Steinbach, Hotez and Williams2,Reference Dougherty, Nascimento, Carapetis, Dougherty, Carapetis, Zühlke and Wilson3} In a previously reported child with acute rheumatic fever and extensive subcutaneous nodules, the nodules occurred in association with severe rheumatic carditis, significant mitral regurgitation, and PR interval prolongation. ^{Reference Singhi, Bobhate and Kappanayil5} Similarly, in the Brazilian series reported by Robazzi et al., the only patient exhibiting the combination of arthritis, erythema marginatum, and subcutaneous nodules also had carditis. ^{Reference Robazzi, de Araújo, Costa Sde, de Oliveira Júnior, Nunes and Guimarães6} In contrast, our patient demonstrated persistently normal electrocardiograms and serial echocardiographic examinations over three months of follow-up, with no evidence of either clinical or subclinical cardiac involvement.

Findings from larger cohorts are consistent with this observation. In a South China cohort, carditis was a predominant manifestation, whereas erythema marginatum and subcutaneous nodules were infrequent findings. ^{Reference Chen, Xie, Gu, Xu, Yang and Yu7} In contrast, our patient fulfilled three major Jones manifestations, including both cutaneous major criteria, yet remained free of clinical, electrocardiographic, and echocardiographic evidence of cardiac involvement throughout follow-up. Collectively, these observations suggest that the coexistence of arthritis, erythema marginatum, and subcutaneous nodules without accompanying carditis is distinctly uncommon.

An additional educational aspect of this report is the serial photographic documentation of erythema marginatum. The rash evolved over several days, displaying changing annular, polycyclic, and serpiginous morphologies with central clearing. Recognition of erythema marginatum may be challenging because of its evanescent nature and because lesions may be less conspicuous in darkly pigmented skin. Previous reports and guideline documents have highlighted the potential for under-recognition of this manifestation in darker skin tones. ^{Reference Gewitz, Baltimore and Tani1,Reference Sharma and Biswal4,Reference Animasahun, Lawani and Lamina8} The serial images presented in this report may therefore assist clinicians practising in endemic regions where acute rheumatic fever remains prevalent but erythema marginatum is infrequently documented.

The persistent absence of carditis also deserves emphasis. Previous reports have demonstrated that cardiac involvement may develop after an initially normal cardiac assessment. Khriesat and Najada described four patients with acute rheumatic fever in whom carditis was absent at presentation but subsequently became apparent during follow-up, underscoring the importance of serial echocardiographic surveillance. ^{Reference Khriesat and Najada9} In contrast, our patient underwent repeated clinical evaluation, electrocardiographic and echocardiographic assessments, including serial follow-up examinations over three months, all of which remained normal. These findings strengthen the conclusion that cardiac involvement was genuinely absent rather than simply delayed in onset.

A further observation was the occurrence of transient inflammatory manifestations during convalescence, including swelling of the lips and subsequent bilateral ocular redness with circumcorneal congestion. Although slit-lamp examination was not performed and a specific ophthalmological diagnosis could not be established, the temporal association with the acute rheumatic episode is noteworthy. Ocular inflammatory manifestations have only rarely been described in association with rheumatic fever and post-streptococcal immune syndromes. Ortiz and colleagues reported severe bilateral scleritis, uveitis, and secondary glaucoma in a patient with rheumatic fever, suggesting that ocular inflammation may occur within the broader spectrum of post-streptococcal immune-mediated disease. ^{Reference Ortiz, Kamerling, Fischer and Baxter10} However, the significance of the lip swelling and ocular findings observed in our patient remains uncertain. In the absence of definitive ophthalmological evaluation and given the self-limited nature of these manifestations, only a temporal association with the acute rheumatic episode can be inferred.