What is Still's disease (Juvenile Rheumatoid Arthritis, JRA)?

From the Guidelines

Still's disease, formerly known as Juvenile Rheumatoid Arthritis (JRA) or Systemic Juvenile Idiopathic Arthritis (sJIA) and Adult-Onset Still's Disease (AOSD), is a single disease entity that affects both children and adults.

Key Features

• Characterized by recurrent spiking fever, skin rash, arthralgia and/or arthritis, and high levels of inflammation 1
• Shared features include serositis, elevated liver function tests (LFTs), and very high serum ferritin levels, as well as the risk of macrophage activation syndrome (MAS) 1
• The presence of arthritis is not essential to make the diagnosis 1

Diagnosis and Management

• Rapid diagnosis is a challenge, and several classification/diagnostic criteria have been proposed to facilitate identification of patients with Still's disease 1
• The disease is associated with a predisposition to life-threatening complications, such as macrophage activation syndrome (MAS), hepatitis, and interstitial lung disease 1
• A unique name, Still's disease, has been chosen to identify the disease across all ages, implying the design of a single trial across all ages, enabling more rapid completion and, in case of positive results, quicker approval by regulatory agencies across all ages 1

Evidence

• Systematic reviews and meta-analyses have shown that sJIA and AOSD are the same disease, with similar clinical manifestations and laboratory findings 1
• The EULAR/PReS recommendations support the use of a single name, Still's disease, for both sJIA and AOSD, and emphasize the need for a common set of diagnostic/classification criteria across all ages 1

From the Research

Definition and Classification of Still's Disease

• Still's disease, also known as Juvenile Rheumatoid Arthritis (JRA), includes systemic juvenile idiopathic arthritis (sJIA) and the adult form of Still's disease (adult-onset Still's disease, AOSD) 2, 3, 4, 5, 6.
• sJIA and AOSD are considered part of the same disease spectrum, with similarities in clinical and biological features, despite differences in age of onset 2, 3, 4, 6.

Clinical Features of Still's Disease

• Common signs and symptoms of sJIA and AOSD include recurrent fever, a fleeting, salmon-colored rash, and arthralgia/arthritis 2, 3, 4, 5, 6.
• The clinical presentation of AOSD is highly variable, with a broad spectrum of disease manifestations, and can be classified into two distinct categories: "systemic" and "articular" 3.
• Macrophage activation syndrome (MAS) is a serious complication of the cytokine storm during the systemic phase of the disease 2, 3.

Diagnosis and Treatment of Still's Disease

• Diagnosis of AOSD can be difficult due to the ambiguity in presentation and lack of serologic markers, often leading to a delay in diagnosis 3, 6.
• The Yamaguchi and Fautrel criteria are the most widely used diagnostic tools in clinical practice for AOSD 3, 6.
• Treatment options for AOSD include non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, conventional synthetic disease-modifying anti-rheumatic drugs, and biologics such as canakinumab, an IL-1 inhibitor 3, 5, 6.
• Targeted therapies such as IL-1 and IL-6 inhibitors have become available for the treatment of sJIA and AOSD, aiming to relieve signs and symptoms, prevent irreversible joint damage, and avoid deleterious side effects of treatment 6.