Still's Disease: Core Symptoms, Less Common Manifestations, and Diagnosis

What are the symptoms of Still's disease?

Still's disease, also known as Adult-Onset Still's Disease (AOSD) in adults and Systemic Juvenile Idiopathic Arthritis (SJIA) in children, is a rare inflammatory condition characterized by a distinctive constellation of systemic symptoms, primarily including high fevers, a characteristic rash, and joint pain.

Understanding Still's Disease

Still's disease is a complex and often challenging condition to diagnose due to its varied presentation and the absence of a single definitive diagnostic test. It is classified as an autoinflammatory disorder, meaning the body's innate immune system becomes overactive, leading to widespread inflammation. While the exact cause remains unknown, it is believed to involve a combination of genetic predisposition and environmental triggers. The symptoms can fluctuate, with periods of active disease (flares) and remission.

Core Systemic Symptoms

The symptoms of Still's disease typically manifest in a characteristic pattern, though not all individuals will experience every symptom. The most common and defining features include:

• Fever: This is one of the most consistent symptoms, often presenting as daily spiking fevers that reach 102°F (39°C) or higher. These fevers typically occur once or twice a day, often in the late afternoon or evening, and return to normal or below-normal temperatures between spikes. This pattern is known as quotidian fever.
• Rash: A distinctive, salmon-pink, non-itchy rash often accompanies the fever spikes. It typically appears on the trunk, upper arms, and thighs, though it can occur anywhere on the body. The rash is usually transient, appearing and disappearing with the fever.
• Joint Pain and Swelling (Arthralgia and Arthritis): Joint involvement is common, ranging from mild joint pain (arthralgia) to significant inflammation and swelling (arthritis). The arthritis can affect any joint but frequently involves the knees, wrists, ankles, elbows, and shoulders. It can be debilitating and, if left untreated, may lead to permanent joint damage.
• Muscle Pain (Myalgia): Generalized muscle aches and pains are frequently reported, often severe and contributing to significant discomfort and fatigue.
• Sore Throat: A non-specific sore throat is a common initial symptom, often preceding other manifestations. It can be persistent and severe, sometimes leading to misdiagnosis as a viral infection.
• Lymph Node Enlargement (Lymphadenopathy): Swollen and tender lymph nodes, particularly in the neck, armpits, and groin, are common. This reflects the systemic inflammatory response.
• Enlarged Spleen and Liver (Splenomegaly and Hepatomegaly): The spleen and liver can become enlarged due to the widespread inflammation, which may be detected during a physical examination or imaging studies.

Less Common, But Significant Symptoms

While less frequent, other symptoms can occur and indicate more severe disease activity:

• Serositis: Inflammation of the serous membranes lining body cavities. This can manifest as:
  • Pericarditis: Inflammation of the sac around the heart, causing chest pain.
  • Pleuritis: Inflammation of the lining around the lungs, leading to chest pain, especially with breathing.
• Abdominal Pain: Non-specific abdominal pain can occur, sometimes related to liver or spleen involvement, or inflammation of the abdominal lining.
• Weight Loss: Chronic inflammation and loss of appetite can lead to unintentional weight loss.
• Anemia: Anemia of chronic disease is common due to the persistent inflammatory state, leading to fatigue and weakness.

Diagnostic Challenges

Diagnosing Still's disease can be challenging due to the non-specific nature of many symptoms, which can mimic infections, other autoimmune diseases, or even certain cancers. Diagnosis relies on a combination of clinical criteria (such as the Yamaguchi or Fautrel criteria), careful exclusion of other conditions, and characteristic laboratory findings. Blood tests often reveal elevated inflammatory markers (e.g., erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]), high white blood cell counts (leukocytosis), and elevated ferritin levels, which can be exceptionally high in Still's disease.

When to Seek Medical Attention

Given the systemic and potentially severe nature of Still's disease, it is crucial to seek prompt medical evaluation if you or someone you know experiences a persistent combination of high fevers, rash, and joint pain, especially if accompanied by other systemic symptoms like a sore throat or muscle aches. Early diagnosis and treatment are vital to manage symptoms, prevent complications, and improve long-term outcomes.

Conclusion

Still's disease is a serious inflammatory condition characterized by a distinct pattern of symptoms, most notably daily high fevers, a salmon-pink rash, and joint pain. While challenging to diagnose, awareness of these key indicators is essential. If these symptoms are present, consulting a healthcare professional, particularly a rheumatologist, for thorough evaluation and management is imperative to ensure an accurate diagnosis and appropriate treatment plan.