Oligoarticular juvenile idiopathic arthritis: epidemiological, clinical, therapeutic and outcome profile of a Tunisian cohort

Abstract

Background

Oligoarticular juvenile idiopathic arthritis (oJIA) is the most common subtype of juvenile idiopathic arthritis and is associated with a risk of chronic anterior uveitis and disease extension. Data from North Africa remain limited. This study aimed to describe the epidemiological, clinical, therapeutic, and outcome profile of Tunisian children with oJIA.

Methods

We conducted a retrospective longitudinal study of children diagnosed with oJIA and followed at a tertiary pediatric rheumatology center in Tunisia between January 1999 and December 2022. Demographic, clinical, ophthalmologic, laboratory, imaging, treatment, and outcome data were collected from medical records. Disease activity was assessed using the Juvenile Arthritis Disease Activity Score based on 10 joints (JADAS-10).

Results

Eighty-two children were included, with a female predominance (67.1%). The mean age at disease onset was 4.4 years and the mean diagnostic delay was 9 months. Antinuclear antibodies were positive in 71% of patients, whereas rheumatoid factor was negative in all tested cases. Uveitis occurred in 20 patients (24.4%) and was asymptomatic in most cases; 85% of affected patients were ANA-positive. Ocular complications developed in 13 of the 20 patients with uveitis, most commonly posterior synechiae and cataract. Disease extension occurred in 18 patients (22%) and was confined to the first two years after disease onset. Methotrexate was prescribed in 52 patients (63.4%), while biologic therapy was indicated in 11 patients and administered to 8 (etanercept, n = 6; adalimumab, n = 2). After a mean follow-up of 5.8 years, disease activity progressively improved, with 88.3% of patients achieving inactive disease at 24 months. Articular complications were uncommon, and acceptable visual acuity was preserved in 14 of the 20 patients with uveitis.

Conclusions

In this single-center North African cohort, oJIA was characterized by early onset, frequent ANA positivity, and a substantial burden of chronic anterior uveitis. Disease extension occurred in approximately one-fifth of patients and was limited to the first two years of disease. Most patients achieved inactive disease despite restricted access to biologic therapies. These findings provide additional data on oJIA from North Africa and highlight the importance of systematic ophthalmologic screening and long-term monitoring.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12887-026-07257-9.

Introduction

Oligoarticular juvenile idiopathic arthritis (oJIA) is the most frequent subtype of juvenile idiopathic arthritis, accounting for approximately 50–60% of cases in Western cohorts [1, 2]. According to the International League of Associations for Rheumatology (ILAR) classification, oJIA is defined by arthritis affecting four or fewer joints during the first six months of disease [1]. It predominantly affects young girls and is typically characterized by early onset before the age of 6 years [2, 3].

Although the articular course is often considered favorable, oJIA carries a significant risk of chronic anterior uveitis, particularly in ANA-positive patients [4–6]. The prevalence of uveitis ranges from 15% to 30% depending on the cohort studied [4, 7]. Early detection is essential, as ocular inflammation may remain asymptomatic and lead to severe complications [5].

Another major clinical issue is disease extension beyond four joints after the initial six months, which occurs in approximately 20–30% of patients and is associated with a more aggressive course [3, 8]. Identifying predictors of extension remains a challenge [9].

Therapeutic management has evolved considerably over the past two decades, with methotrexate remaining the cornerstone conventional disease-modifying therapy [10], and biologic agents significantly improving outcomes in refractory cases [11, 12]. However, access to advanced therapies remains unequal worldwide [13].

Despite extensive data from Europe and North America, information from North African populations remains limited. Regional epidemiological and outcome data are essential to better understand potential variations in disease expression and management.

Methods

Study design and setting

We conducted a retrospective, longitudinal, single-center study at the Department of Pediatrics, Béchir Hamza Children’s Hospital, Tunis, Tunisia, a tertiary referral center with pediatric rheumatology activity. The study covered a 23-year period from January 1999 to December 2022.

Study population

We reviewed the medical records of children followed for oligoarticular juvenile idiopathic arthritis. The diagnosis was based on the International League of Associations for Rheumatology classification criteria. Oligoarticular JIA was defined as arthritis beginning before the age of 16 years, persisting for at least 6 weeks, and involving one to four joints during the first 6 months of disease.

Patients were classified as having persistent oligoarticular JIA when fewer than five joints remained involved after the first 6 months, and extended oligoarticular JIA when more than four joints became involved after the first 6 months.

Inclusion and exclusion criteria

Children were included if they fulfilled ILAR criteria for oligoarticular JIA and had a minimum follow-up duration of 6 months. Patients were excluded if they had psoriasis or a first-degree family history of psoriasis, arthritis in a boy older than 6 years with HLA-B27 positivity, enthesitis-related arthritis, sacroiliitis, inflammatory bowel disease-associated arthritis, acute anterior uveitis, a first-degree family history of spondyloarthropathy, persistent rheumatoid factor positivity, systemic JIA, another associated inflammatory disease, incomplete medical records, or follow-up shorter than 6 months. Alternative diagnoses were excluded before retaining the diagnosis of oligoarticular JIA.

Data collection

Data were collected from medical records using a standardized data extraction form. The following variables were recorded: demographic characteristics, age at disease onset, age at diagnosis, diagnostic delay, referral pathway, family and personal medical history, clinical presentation, number and distribution of affected joints, laterality, morning stiffness, synovitis, joint effusion, flexion deformity, limitation of motion, ophthalmologic findings, laboratory parameters, imaging findings, treatment modalities, adverse events, disease extension, relapse, complications, and final outcome.

Laboratory assessment included erythrocyte sedimentation rate, C-reactive protein, complete blood count, serum protein electrophoresis when available, antinuclear antibodies, rheumatoid factor, anti-cyclic citrullinated peptide antibodies when available, and additional investigations performed to exclude differential diagnoses.

Ophthalmologic assessment

All patients underwent ophthalmologic assessment by pediatric ophthalmologists using slit-lamp examination at diagnosis and throughout follow-up. Screening and monitoring were performed according to the 2019 American College of Rheumatology/Arthritis Foundation recommendations for JIA-associated uveitis. Patients considered at high risk for uveitis underwent ophthalmologic screening every three months, while follow-up intervals were subsequently adapted according to ophthalmologic findings and disease activity. High-risk patients were defined as children with oligoarticular JIA, positive antinuclear antibodies, age at disease onset younger than 7 years, and disease duration of 4 years or less, in accordance with the ACR/AF recommendations. Information regarding the occurrence of uveitis, age at onset, delay from arthritis onset, laterality, clinical presentation, ocular complications, treatment, and outcome was extracted from medical records.

Ocular complications included decreased visual acuity, blindness, posterior synechiae, cataract, band keratopathy, glaucoma, seclusion pupillae, and pupillary deformity. Uveitis was classified as absent, moderate, or severe according to relapse frequency, duration, response to topical therapy, and presence of ocular complications.

Disease activity and outcomes

Disease activity was assessed using the Juvenile Arthritis Disease Activity Score based on 10 joints. JADAS-10 was calculated at baseline and at 3, 6, 12, and 24 months when the required components were available in the medical records. The score incorporated physician global assessment, parent or patient global assessment, active joint count, and erythrocyte sedimentation rate.

Disease activity states were categorized as inactive disease, minimal disease activity, moderate disease activity, or high disease activity according to validated JADAS-10 cut-off values. Complete remission was defined as achievement of inactive disease. Partial remission was defined as improvement in JADAS-10 without reaching inactive disease. Lack of response was defined as unchanged or increased JADAS-10.

Articular relapse was defined as recurrence of at least moderate disease activity after a period of remission. Ocular relapse was defined as recurrence of active uveitis after remission. Functional and structural outcomes were assessed using available clinical data, including persistent limitation of motion, fixed joint deformity, limb asymmetry, need for rehabilitation, and need for orthopedic surgery. Standardized CHAQ/HAQ scores were not available because of the retrospective design.

Treatment assessment

Therapeutic data included use of non-steroidal anti-inflammatory drugs, aspirin, systemic corticosteroids, intra-articular corticosteroid injections, methotrexate, and biologic disease-modifying antirheumatic drugs. For each treatment, the drug used, dose, route of administration, duration, response, and adverse events were recorded. Biologic therapy indication, agent used, access limitations, and outcome were also collected.

Due to the retrospective design and the long study period, some variables were not available for all patients. Missing data were mainly related to laboratory investigations and disease activity assessments performed outside the institution. Available-case analysis was used, and percentages were calculated using the number of patients with available data for each variable.

Statistical analysis

Statistical analyses were performed using SPSS software. Quantitative variables were summarized as means and standard deviations or medians and ranges, according to data distribution. Qualitative variables were expressed as frequencies and percentages. Given the descriptive and retrospective nature of the study, analyses were limited to descriptive statistics. Missing data were reported when applicable. No inferential analyses were performed, and the findings should therefore be interpreted as descriptive and hypothesis-generating.

Results

Baseline characteristics

A total of 82 children with oligoarticular juvenile idiopathic arthritis were included over the 23-year study period. The cohort included 56 girls (67.1%) and 26 boys (32.9%), with a male-to-female ratio of 0.46. Disease onset occurred before the age of 5 years in 57 patients (69%). The mean age at disease onset was 4 years and 5 months, ranging from 9 months to 13 years and 4 months.

The mean diagnostic delay was 9 months, with a range of 2 to 48 months. A diagnostic delay longer than 2 years was observed in 17 patients. This delay was mainly attributed to mild disease activity with intermittent symptoms responsive to symptomatic treatment, or to initial diagnostic errors.

A family history of rheumatic or autoinflammatory disease was recorded in 13 patients (15.8%). Consanguinity was reported in 8 patients. Personal medical history was noted in 36 patients and included various conditions, without a predominant associated disorder.

The mean follow-up duration was 5.8 years, ranging from 6 months to 14 years.

Clinical manifestations

Joint involvement was the presenting manifestation in nearly all patients. At the initial rheumatology assessment, active arthritis was documented in 52 patients (63.4%), while 22 patients (26.8%) already exhibited residual joint stiffness with or without active synovitis. Eight patients (9.8%) had a normal musculoskeletal examination at presentation despite a history of previous arthritis episodes. Uveitis was the sole presenting manifestation in two patients, whereas concomitant ocular and articular involvement at presentation was observed in one patient. Fever was uncommon and was reported in only five cases.

Intermittent limping was the most frequently reported symptom (n = 32), followed by delayed acquisition of walking (n = 4), visual blurring (n = 3), writing difficulties (n = 2), and lower-limb asymmetry (n = 1). Morning stiffness was consistently reported and lasted between 5 and 40 min. Arthralgia affecting sites other than the clinically involved joints was noted in 10 patients.

At disease onset, 29 patients (35.4%) presented with monoarthritis, most commonly involving the knee. Large joints were predominantly affected, and joint involvement was unilateral in 44 patients (53.7%). Among patients with bilateral arthritis, the distribution was asymmetrical in most cases. Six patients already had more than four affected joints at their first specialist evaluation. Clinical examination revealed synovitis in 71 patients (86.6%), joint effusion in 60 (73.2%), limitation of motion in 55 (67.1%), and flexion contracture in 42 (51.2%). No shoulder, thoracic spine, or lumbar spine involvement was observed.

The distribution of affected joints at presentation is summarized in Table 1.

Table 1.

Distribution of joint involvement at presentation

Joint involved	n (%)
Knee	68 (82.9)
Ankle	18 (21.9)
Wrist	13 (15.8)
Proximal interphalangeal joints	9 (10.9)
Elbow	5 (6)
Hip	3 (3.6)
Cervical spine	1 (1.2)
First toe interphalangeal joint	1 (1.2)
Metacarpophalangeal joints	1 (1.2)

Laboratory and imaging findings

Laboratory abnormalities were heterogeneous and reflected the variable inflammatory activity of oligoarticular JIA. Inflammatory markers were inconsistently elevated, and hematological abnormalities were generally mild. Immunological testing revealed a high frequency of antinuclear antibody positivity, whereas rheumatoid factor was consistently negative in all tested patients.

Conventional radiographs were normal in most patients at diagnosis, with structural joint damage observed only in a minority of cases. In contrast, musculoskeletal ultrasound frequently detected abnormalities, including clinically silent synovitis and joint effusion, even in patients with normal radiographic findings. Magnetic resonance imaging was mainly performed in selected patients with monoarticular disease or diagnostic uncertainty and provided additional evidence of active synovitis and joint inflammation.

The main laboratory and imaging findings are summarized in Table 2.

Table 2.

Laboratory and imaging findings

Variable	n/N (%)
Elevated ESR	34/82 (42)
Elevated CRP	21/82 (26)
Anemia	20/82 (23)
Thrombocytosis	22/82 (27)
Elevated α2-globulin fraction	32/72 (44)
ANA positivity	59/82 (71)
Rheumatoid factor positivity	0/70 (0)
Anti-CCP positivity	3/62 (4.8)
Normal radiographs	61/80 (76)
Bone erosions on radiographs	3/80 (3.7)
Joint space narrowing	4/80 (5.0)
Abnormal ultrasound findings	62/70 (88.6)
Clinically silent synovitis detected by ultrasound	5/70 (7.1)
Abnormal MRI findings	25/26 (96.2)

Ocular involvement

Uveitis occurred in 20 patients (24.4%) during follow-up, including 13 girls and 7 boys (female-to-male ratio: 1.8). Antinuclear antibodies were positive in 17 of the affected patients (85%). Ocular involvement was bilateral in 9 cases (45%). All patients developed chronic anterior non-granulomatous uveitis, while associated posterior segment involvement was observed in only one patient.

Uveitis was asymptomatic in most cases and was detected through routine ophthalmologic screening. Only three patients presented with visual symptoms, including decreased visual acuity in two cases and blurred vision associated with leukocoria in one case. Notably, none of the patients presented with a red eye, even during severe inflammatory episodes.

The mean age at uveitis onset was 6 years and 3 months (range: 2–18 years). The mean interval between arthritis onset and uveitis diagnosis was 15 months, with a maximum delay of 8 years and 4 months. Nearly half of the patients developed uveitis during the first year following arthritis onset. In two patients, uveitis preceded the onset of arthritis by 3 and 7 months, respectively, and was already complicated at diagnosis.

Uveitis was observed in both persistent and extended oligoarticular JIA, affecting 26% and 16% of patients, respectively. Associated ocular conditions included dry eye syndrome (n = 4), allergic conjunctivitis (n = 2), divergent strabismus (n = 1), hyperopia (n = 1), and myopia (n = 1).

Treatment

Non-steroidal anti-inflammatory drugs (NSAIDs) were the most commonly used first-line therapy and were prescribed in 81% of patients. Ibuprofen was the preferred agent, followed by indomethacin and aspirin. Clinical response to first-line treatment was variable, with approximately one-third of patients achieving complete remission, while others required treatment escalation because of persistent disease activity or intolerance.

Intra-articular corticosteroid injections were administered to 22 patients, predominantly those with persistent oligoarticular disease. In six patients, intra-articular therapy alone achieved sustained disease control without the need for disease-modifying antirheumatic drugs (DMARDs). Systemic corticosteroids were used only in selected situations, including severe uveitis threatening visual prognosis or highly active disease not amenable to local treatment.

Methotrexate was the first-line DMARD and represented the cornerstone of treatment escalation. Overall, 52 patients (63.4%) received methotrexate, including all patients with extended oligoarticular JIA. Most patients received oral methotrexate, whereas the subcutaneous route was reserved for inadequate response or gastrointestinal intolerance. Treatment was generally well tolerated, and adverse events were infrequent and manageable.

Biologic therapy was indicated in 11 patients because of refractory articular or ocular disease. However, only eight patients received biologic agents owing to limitations in health insurance coverage. Etanercept and adalimumab were the biologics used in our cohort and were systematically combined with methotrexate. Most treated patients achieved complete remission after biologic initiation.

Topical ophthalmic corticosteroids were prescribed in all patients with anterior uveitis and constituted the mainstay of local ocular treatment.

Treatment strategies and outcomes are summarized in Table 3.

Table 3.

Therapeutic management of the study population

Treatment modality	n (%)
NSAIDs	66 (80.5)
Intra-articular corticosteroid injections	22 (26.8)
Systemic corticosteroids	11 (13.4)
Methotrexate	52 (63.4)
Oral methotrexate	44 (53.7)
Subcutaneous methotrexate	8 (9.8)
Methotrexate + intra-articular corticosteroids	16 (19.5)
Biologic therapy indicated	11 (13.4)
Biologic therapy received	8 (9.8)
Etanercept	6 (7.3)
Adalimumab	2 (2.4)

Outcomes and disease activity

After a mean follow-up of 5.8 years (range: 6 months–14 years), 64 patients (78%) maintained a persistent oligoarticular disease course, whereas 18 patients (22%) developed extended oligoarticular JIA. Disease extension occurred within the first two years after disease onset in all affected patients. Secondary joint involvement most frequently affected the small joints of the hands and the cervical spine.

Disease activity progressively improved during follow-up. According to the JADAS-10, the proportion of patients with inactive disease increased from 7.3% at baseline to 69% at 6 months, 85.6% at 12 months, and 88.3% at 24 months (Fig. 1). Conversely, high disease activity decreased from 20% at baseline to 6% at 12 months and was no longer observed at 24 months. At the 24-month evaluation, 43 patients had achieved inactive disease off treatment, while 24 had inactive disease under ongoing therapy. Three patients continued to exhibit moderate disease activity; two of them had an unmet indication for biologic therapy because of limited insurance coverage.

Fig. 1.

Evolution of disease activity according to JADAS-10 categories during the first 24 months of follow-up. The proportion of patients achieving inactive disease (ID) increased progressively, while moderate (MDA) and high disease activity (HDA) declined markedly. Most disease activity transitions occurred within the first year

Regarding ocular outcomes, 62 patients (75.6%) did not develop uveitis during follow-up. Among the 20 patients with uveitis, 13 (65%) experienced at least one ocular complication. The most frequent complications were posterior synechiae (n = 11), cataract (n = 6), band keratopathy (n = 4), pupillary seclusion (n = 3), and neovascular glaucoma (n = 1). One patient developed permanent unilateral blindness and another developed amblyopia. Despite these complications, acceptable visual acuity was preserved in 14 of the 20 affected patients.

Articular complications were uncommon and included fixed deformities in four patients, persistent limitation of joint mobility in five patients, and lower-limb length discrepancy in one patient. These complications occurred exclusively in patients with prolonged diagnostic delay and extended disease. During follow-up, 11 patients (14.2%) experienced at least one relapse, most commonly within the first two years after diagnosis. Ocular and articular relapses occurred independently, with no concomitant reactivation observed.

Long-term outcomes and disease activity are summarized in Table 4.

Table 4.

Long-term outcomes of patients with oligoarticular JIA

Outcome	n (%)
Mean follow-up duration	5.8 years
Persistent oligoarticular JIA	64 (78.0)
Extended oligoarticular JIA	18 (22.0)
Inactive disease at 24 months	68/76 (88.3)
Moderate disease activity at 24 months	3/76 (3.9)
Patients without uveitis	62 (75.6)
Uveitis with complications	13/20 (65.0)
Permanent unilateral blindness	1 (1.2)
Articular deformities	4 (4.9)
Limitation of joint mobility	5 (6.1)
Limb-length discrepancy	1 (1.2)
Relapses during follow-up	11 (14.2)

Discussion

Main findings

This study provides one of the largest single-center cohorts of oligoarticular juvenile idiopathic arthritis reported from North Africa. Our patients were characterized by a marked female predominance, early disease onset, and a high prevalence of antinuclear antibody positivity. Uveitis affected nearly one-quarter of the cohort and was frequently asymptomatic, highlighting the importance of systematic ophthalmologic screening. Although approximately one-fifth of patients developed extended disease, most achieved favorable outcomes, with nearly 90% reaching inactive disease after 24 months of follow-up. Despite restricted access to biologic therapies, methotrexate-based treatment strategies provided satisfactory disease control in the majority of patients.

Epidemiological and clinical profile

The epidemiological and clinical profile observed in our cohort was broadly consistent with the classical phenotype of oligoarticular JIA described in European and North American populations. The predominance of girls, early disease onset, asymmetric lower-limb involvement, and preferential knee involvement observed in our patients are well-recognized characteristics of this disease subtype [2, 3]. Similarly, the proportion of patients who developed extended disease (22%) falls within the range reported in Western cohorts, where extension rates generally vary between 20% and 30% [7, 8].

Our findings were also largely comparable to those reported from other Middle Eastern and North African (MENA) countries. Studies from Jordan, Saudi Arabia, Egypt, and Morocco have consistently described a predominance of female patients, early disease onset, and oligoarticular disease as one of the most frequent JIA subtypes [14–17]. These similarities suggest that the overall clinical phenotype of oligoarticular JIA remains relatively stable across different geographic and ethnic populations.

Nevertheless, the diagnostic delay observed in our cohort deserves attention. Although the mean delay was less than one year, a substantial proportion of patients experienced delays exceeding two years before diagnosis. Similar observations have been reported in several MENA cohorts and may reflect the insidious onset of oligoarticular JIA, the intermittent nature of symptoms, and the limited availability of specialized pediatric rheumatology services in some regions [14, 17]. These findings underscore the importance of increasing awareness of pediatric rheumatic diseases among primary care physicians, pediatricians, orthopedic surgeons, and ophthalmologists to facilitate earlier referral and treatment.

Uveitis: frequency and severity

Uveitis remains one of the most important extra-articular manifestations of oligoarticular JIA and a major determinant of long-term morbidity. In our cohort, uveitis occurred in 24.4% of patients, which is consistent with the prevalence reported in large European cohorts, generally ranging from 15% to 30% [4, 5, 7]. Similarly, most affected patients were ANA-positive, reinforcing the well-established association between ANA positivity and increased risk of JIA-associated uveitis [4, 5].

A notable finding in our study was the predominantly asymptomatic presentation of ocular inflammation. Only three patients reported visual symptoms, whereas the vast majority of cases were detected through systematic ophthalmologic screening. This observation is in agreement with previous studies showing that chronic anterior uveitis in JIA often follows an insidious course, with minimal ocular symptoms despite ongoing inflammation [5, 18]. The absence of ocular redness, even in severe cases, further highlights the limitations of symptom-based detection strategies and supports current recommendations advocating regular slit-lamp examinations in high-risk patients [4].

Although the frequency of uveitis in our cohort was comparable to that reported internationally, the proportion of patients who developed ocular complications was relatively high. Nearly two-thirds of affected patients experienced at least one complication, most commonly posterior synechiae and cataract. Several factors may contribute to this finding, including delayed diagnosis of ocular disease, limited access to specialized ophthalmologic care in the early years of the study period, and the silent nature of chronic anterior uveitis itself. Similar observations have been reported in historical cohorts, whereas more recent studies suggest that earlier screening and prompt initiation of systemic immunomodulatory therapy have reduced the burden of vision-threatening complications [5, 19].

The biological mechanisms underlying the increased susceptibility of ANA-positive children to uveitis remain incompletely understood. Current evidence suggests that ANA positivity may reflect a distinct immunological phenotype characterized by persistent autoreactive immune responses and chronic low-grade ocular inflammation [20]. While our descriptive design does not allow assessment of risk factors, the high proportion of ANA-positive patients among those with uveitis supports the need for vigilant ophthalmologic surveillance in this subgroup.

Disease extension and long-term outcomes

Disease extension occurred in 22% of our patients, a proportion that closely mirrors the rates reported in European cohorts, where approximately one-fifth to one-third of children with oligoarticular JIA eventually develop extended disease [7, 8]. Notably, all extension events in our cohort occurred within the first two years after disease onset. This observation is consistent with previous studies demonstrating that the risk of extension is highest during the early disease course and decreases substantially thereafter [8, 21]. From a clinical perspective, these findings reinforce the concept that the first two years represent a critical period for close monitoring and therapeutic decision-making.

The pattern of extension observed in our cohort, predominantly involving the small joints of the hands and the cervical spine, reflects progression toward a more extensive inflammatory phenotype. Previous studies have shown that extended oligoarticular JIA is associated with greater disease burden, increased exposure to disease-modifying therapies, and a less favorable long-term prognosis than persistent oligoarticular disease [7, 9]. In our study, all patients with extended disease required methotrexate, supporting the greater therapeutic complexity of this subgroup.

Despite the occurrence of disease extension in a subset of patients, overall outcomes were favorable. Disease activity progressively declined throughout follow-up, with nearly 90% of patients achieving inactive disease after 24 months. The rapid increase in inactive disease rates during the first year suggests that early therapeutic intervention was effective in controlling inflammation. Comparable improvements have been reported in contemporary JIA cohorts, reflecting advances in treatment strategies and tighter disease monitoring [6, 22].

Long-term structural complications were uncommon and were observed almost exclusively in patients with extended disease and prolonged diagnostic delay. This finding highlights the importance of early diagnosis and prompt initiation of treatment to prevent irreversible joint damage. Interestingly, relapse rates remained relatively low, and ocular and articular relapses occurred independently, emphasizing the heterogeneous nature of disease activity in oligoarticular JIA and the need for parallel rheumatologic and ophthalmologic follow-up.

Therapeutic management in a resource-limited setting

The therapeutic approach adopted in our cohort was largely consistent with contemporary treatment recommendations for oligoarticular JIA, with a stepwise escalation from non-steroidal anti-inflammatory drugs and intra-articular corticosteroid injections to methotrexate and biologic therapies when required [10, 23]. Methotrexate represented the cornerstone of treatment escalation and was prescribed to nearly two-thirds of patients, including all children who developed extended disease. This finding is consistent with current international practice, where methotrexate remains the preferred first-line disease-modifying antirheumatic drug for patients with persistent disease activity or poor prognostic features [10, 24].

An important observation in our study was the relatively limited use of biologic therapies. Although biologic treatment was indicated in 11 patients, only eight ultimately received these agents because of restrictions related to health insurance coverage. Similar disparities in access to advanced therapies have been reported across several low- and middle-income countries, where economic constraints remain a major determinant of treatment availability [17, 25]. Consequently, therapeutic decisions may be influenced not only by disease severity but also by healthcare system limitations.

Despite these constraints, overall outcomes remained favorable, with high rates of inactive disease and relatively few long-term articular complications. Several factors may explain these results, including early initiation of methotrexate in patients with persistent disease activity, the extensive use of intra-articular corticosteroid injections, and close follow-up in a specialized pediatric rheumatology center. These findings suggest that satisfactory disease control can still be achieved in resource-limited settings when conventional therapies are appropriately implemented and monitored.

Nevertheless, the observation that two patients with persistent moderate disease activity had an unmet indication for biologic therapy illustrates the potential impact of restricted access to advanced treatments on long-term outcomes. As biologic agents have substantially improved disease control and visual prognosis in refractory articular and ocular disease [11, 12, 19], expanding equitable access to these therapies remains an important challenge for healthcare systems across North Africa and other resource-constrained regions.

North African perspective

One of the main contributions of the present study is the provision of detailed long-term data from a North African population, a region that remains markedly underrepresented in the pediatric rheumatology literature. Most available evidence on oligoarticular JIA originates from Europe and North America, while reports from North Africa are scarce and often limited by small sample sizes or heterogeneous JIA populations [14–17]. Consequently, important regional differences in disease presentation, healthcare access, and long-term outcomes remain insufficiently characterized.

Our findings suggest that Tunisian children with oligoarticular JIA share many of the epidemiological and clinical characteristics reported worldwide, including female predominance, early disease onset, frequent ANA positivity, and a substantial risk of chronic anterior uveitis. However, several observations may reflect regional healthcare realities. Diagnostic delays remained relatively common, ocular complications were frequent among patients with uveitis, and access to biologic therapies was occasionally restricted by reimbursement limitations. Similar challenges have been described in other countries from Africa and the Middle East, highlighting persistent inequalities in access to specialized pediatric rheumatology and ophthalmology services [17, 25].

At the same time, the favorable long-term outcomes observed in our cohort demonstrate that effective disease control can be achieved even in resource-constrained settings when patients benefit from structured multidisciplinary care and regular follow-up. The combination of systematic ophthalmologic screening, early methotrexate use, and close monitoring may have contributed to the high rates of inactive disease observed in our study. These findings are particularly relevant for healthcare systems across North Africa, where access to biologic therapies remains variable and optimization of conventional treatment strategies continues to play a central role.

Taken together, our results contribute to filling an important knowledge gap regarding oligoarticular JIA in North Africa and support the need for future multicenter regional registries. Such collaborative initiatives would allow more robust evaluation of disease phenotypes, treatment patterns, and long-term outcomes across diverse North African populations.

Strengths and limitations

The strengths of this study include the relatively large number of patients with oligoarticular JIA, the long follow-up duration, and the detailed characterization of ocular, therapeutic, and long-term outcomes in a North African population. In addition, all patients were managed in a single tertiary referral center, ensuring consistent diagnostic and therapeutic approaches throughout the study period. However, several limitations should be acknowledged. The retrospective design may have resulted in missing data and information bias, particularly for variables that were not systematically recorded during the early years of the study. The single-center setting may also limit the generalizability of our findings to other populations. Finally, the descriptive nature of the study precluded the identification of independent predictors of uveitis, disease extension, or long-term outcomes.

Conclusion

In this single-center retrospective cohort of Tunisian children with oligoarticular juvenile idiopathic arthritis, the disease was characterized by female predominance, early onset, frequent antinuclear antibody positivity, and a substantial burden of chronic anterior uveitis. Disease extension occurred in approximately one-fifth of patients and was confined to the first two years after disease onset. Despite limited access to biologic therapies, most patients achieved inactive disease during follow-up, while ocular complications remained an important source of morbidity. These findings provide additional data on oligoarticular JIA from North Africa and underscore the importance of early diagnosis, regular ophthalmologic screening, and close long-term monitoring. Larger multicenter studies are needed to better characterize disease patterns and outcomes across the region.

Authors’ contributions

HH contributed to study conception and design.IT collected clinical data.MJ performed statistical analysis.MHL drafted the manuscript.All authors critically revised the manuscript and approved the final version.

Funding

No specific funding was received.

Data availability

The dataset supporting the conclusions of this article is included within the article and its additional file.

Declarations

Ethics approval and consent to participate

The study was approved by the Ethics Committee of Children Hospital Béchir Hamza, University of Tunis El Manar, Tunis, Tunisia.Given the retrospective design of the study, the Ethics Committee waived the requirement for written informed consent.All procedures performed in this study involving human participants were conducted in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.