Introduction

Oligoarthritis alternatively referred to as oligoarticular juvenile idiopathic arthritis is the most prevalent form of juvenile idiopathic arthritis (JIA). JIA broadly refers to several kinds of chronic conditions characterised by joint inflammation (arthritis), which can cause pain in your joints, swelling, stiffness, and loss of movement. In Latin, the word “ Oligo” means “ Few”. Oligoarthritis refers to the condition where two to four joints are affected by arthritis.¹ 

Understanding its symptoms, diagnostic approaches, and treatment modalities is crucial for both patients and healthcare professionals. In this exploration, we delve into the details of oligoarthritis, examining its clinical features, potential causes, diagnostic procedures, and the diverse strategies employed in its management. As we unravel the complexities of this condition, we gain insights into the challenges faced by individuals with oligoarthritis and the 

the evolving landscape of medical interventions designed to alleviate symptoms and improve the overall quality of life.

Who does Oligoarthritis affect?

50 to 80% of children diagnosed with juvenile idiopathic arthritis have oligoarthritis. This condition will primarily affect your joints located in the lower extremities. So oligoarthritis is defined as an arthritis that affects four or fewer joints within the initial 6 months of the disease.²

How common is Oligoarthritis?

The most prominent form of juvenile idiopathic arthritis is oligoarthritis. Juvenile idiopathic arthritis is estimated to affect between 4 and 16 per 1000 children in Europe and North America. Oligoarthritis affects about half of the children who are diagnosed with Juvenile idiopathic arthritis (JIA).¹ 

Signs and Symptoms

• Blurry vision
• Weakness and Fatigue
• Joint discomfort
• Joint stiffness
• Joint tenderness or swelling¹  

Etiology

Environmental Factors 

Exposure to general toxins or pollutants may contribute to the development of Oligoarthritis. 

Genetic Factors

There is evidence that genetic factors play a role in the development of Oligoarthritis. For example, a family history of oligoarthritis may increase the risk.

Infectious Causes

Some cases of oligoarthritis may be triggered by infections. Examples include reactive arthritis, which can occur following certain infections like those caused by Salmonella, Shigella, Campylobacter, or Chlamydia. 

Autoimmune Diseases

Oligoarthritis can be associated with autoimmune conditions such as rheumatoid arthritis, and psoriatic arthritis. In these cases, the immune system mistakenly attacks the joints leading to inflammation and joint damage. 

Trauma or injury 

Physical trauma or injury to a joint can sometimes trigger inflammation and can lead to oligoarthritis. 

Types of Oligoarthritis

1-4 joints are affected by arthritis within the initial six months of the disease⁸. There are two subcategories identified:- 

1. Persistent Oligoarthritis

During the course of the disease, no more than four joints are affected.

2. Extended Oligoarthritis

More than four joints would be affected beyond the initial six months of the disease.³ 

Diagnosis

Oligoarthritis will be diagnosed subsequently following a comprehensive medical history review by the physician. As a result of physical examination, which excludes conditions with similar symptoms, a diagnosis is made for your child. 

Your physician might suggest imaging tests, such as an X-ray or MRI, to visualise the affected joints in order to confirm the diagnosis. Additionally, your physician might suggest a laboratory examination, such as joint fluid, blood, or urine test, to identify the source of your child’s symptoms.¹   

Laboratory Evaluation 

While laboratory indicators of inflammation in children with oligoarthritis may remain normal, there is a possibility of experiencing modest to moderate elevations in C-reactive protein levels and erythrocyte sedimentation rate (ESR). Elevated levels of haemoglobin, white blood cells, and platelets are usually normal, and the presence of any abnormalities should lead to a diagnosis other than oligoarthritis. 

Radiographic Evaluation  

Radiographic alterations in oligoarthritis resemble those observed in other forms of arthritis, though to a lesser extent. In a follow-up study conducted by K.oen, M.Reed, et al, narrowing of joint space was observed in 5% of the 97 children who underwent a follow-up study on pauciarticular juvenile idiopathic arthritis. This percentage increased to around 15% at a median of 6.2 years after the onset of the disease. 10% of children diagnosed with early disease and 25% of children six years later exhibited erosions. Bone hypertrophy was observed in 20% of children early in the disease and slightly higher frequency later in the disease course.⁴  

Treatment and management

A timely and precise diagnosis is critical for achieving the most favourable treatment outcome when managing oligoarthritis. Early in the progression of the disease, medical attention might not be sought due to the subtle nature of the signs and symptoms. An initial examination may suggest that the management of oligoarthritis in children is a straightforward process. However prompt, cautious treatment by a qualified group of health professionals is required to ensure the best possible outcome. The ultimate goal of treatment should be the complete cessation of all indications and manifestations of joint inflammation. Oligoarthritis should be initially managed with comprehensive clinical assessments and musculoskeletal evaluation.⁵   

Possible treatment aspects include : 

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) 

These medications reduce joint swelling and reduce discomfort.

Corticosteroid Injection 

Your doctor may administer a corticosteroid injection into the affected joint of your child. The patient may also be prescribed a corticosteroid tablet for oral administration, as directed by their physician.

Disease-modifying anti-rheumatic Medications (DMARDs)

By inhibiting the immune system’s attack on your child’s joints, DMARDs prevent bone and joint injury. DMARDs are a secondary line of defence, in the event that the injections fail to be effective. DMARDs may be administered as a treatment induction agent.  

Biologics

Biologic medications are prescribed to the joints that do not exhibit therapeutic response.

Physical and occupational therapy

By increasing flexibility and muscle tone, physical and occupational therapy enhances mobility. Your child's developing joints may be safeguarded and a range of motion may be restored through the use of bracing.¹     

Prognosis

What to anticipate in the event that my child develops oligoarthritis? 

Oligoarthritis impacts the joints within your child’s body, potentially impeding their ability to engage in physical activities comparable to other children their age, particularly in the absence of treatment. This condition is typically outgrown by the time they enter into adulthood. Certain children may develop joint discomfort in other areas of their bodies as they age. Physical therapy enhances your child’s mobility, enabling them to play and move, while treatment alleviates joint discomfort and rigidity.¹ 

FAQs

What is the meaning of Oligoarthritis?

Oligoarthritis is characterised by joint stiffness and swelling; large joints, including the knees, elbows, and ankles, are frequently affected. It is diagnosed in children and teens below 16 years of age. In some cases, this condition resolves over time, while others progress and invade additional anatomical sites in adulthood. Prolonged treatment substantially reduces symptoms and minimises joint impairment.¹ 

What is the cause of Oligoarticular arthritis?

The potential causes of Oligoarticular arthritis include:

• Juvenile Idiopathic Arthritis (JIA): Oligoarticular arthritis is a common presentation in children with JIA, which is a group of chronic arthritic conditions with an onset before the age of 16. In JIA, the immune system mistakenly attacks the joints, leading to inflammation.

• Rheumatoid Arthritis (RA): While rheumatoid arthritis typically involves multiple joints, it can initially present as oligoarticular arthritis. RA is an autoimmune condition where the immune system attacks the synovium (the lining of the membranes surrounding joints)

• Psoriatic Arthritis: This form of arthritis is associated with psoriasis, a skin condition. Psoriatic arthritis can affect a few joints, leading to oligoarticular involvement

• Infectious Causes: Certain infections can lead to arthritis affecting a small number of joints. For example, Lyme disease, caused by a bacterium transmitted through tick bites, can initially present as oligoarticular arthritis

• Reactive Arthritis: This type of arthritis can occur in response to an infection in another part of the body, often the gastrointestinal or genitourinary tract. Reactive arthritis can be oligoarticular and may be triggered by infections such as Chlamydia or Salmonella

• Spondyloarthropathies: Oligoarticular arthritis can be part of spondyloarthropathies, a group of inflammatory rheumatic diseases that also affect the spine. Ankylosing spondylitis and psoriatic arthritis are examples of spondyloarthropathies

• Post-Infectious Arthritis: Following certain infections, individuals may develop arthritis affecting a small number of joints. This can be a reactive response to the preceding infection

• Autoinflammatory Syndromes: Some rare autoinflammatory syndromes can cause recurrent episodes of arthritis involving a limited number of joints. Examples include familial Mediterranean fever (FMF) and periodic fever syndromes

• Undifferentiated Arthritis: In some cases, joint inflammation may not fit neatly into a specific category, leading to a diagnosis of undifferentiated arthritis

What is the difference between monoarthritis and oligoarthritis?

Monoarthritis is characterised by the inflammation of a single joint and is distinguished by symptoms including joint swelling, pain, warmth, and occasionally fever.⁶ Oligoarthritis is characterised by the involvement of two to four joints within the initial six months of the disease. 

What are the criteria for Oligoarthritis?

Persistent Oligoarthritis is classified as having four or fewer affected joints after the initial six months whereas Extended oligoarthritis is classified as having more than four affected joints after the initial six months.⁷ 

Summary 

Oligoarthritis is the prevalent form of juvenile idiopathic arthritis (JIA). In Latin “Oligo” means “few”. Oligoarthritis refers to a condition where two to four joints are affected by arthritis. The most prominent form of juvenile arthritis is Oligoarthritis. 50 to 80 % of children diagnosed with juvenile arthritis have Oligoarthritis. Joint stiffness and Joint discomfort are the main signs and symptoms of Oligoarthritis. Oligoarthritis is caused by environmental factors, genetic factors, infections, autoimmune disease, trauma, or joint injury. 

Oligoarthritis is broadly categorised into Extended Oligoarthritis and Persistent Oligoarthritis. Diagnosis of Oligoarthritis involved laboratory evaluation and radiographic evaluation. Oligoarthritis can be treated using Nonsteroidal Anti-inflammatory drugs, corticosteroid injections, Disease- modifying-anti-rheumatic medication, Biologics, and physical therapy.