Adult-onset Still’s disease

1) Disease Description (Causes and Symptoms)

• Definition: Adult-Onset Still's disease (AOSD) is a systemic autoimmune and autoinflammatory disease that affects the entire body and presents with clinical features similar to systemic juvenile idiopathic arthritis (systemic-onset juvenile rheumatoid arthritis). It most commonly develops between the ages of 16 and 35.
• Causes and pathophysiology: Although the exact cause is unknown, excessive release of inflammatory cytokines (including IL‑1, IL‑6, and IL‑18) following external stimuli such as viruses or bacteria in people with a genetic predisposition is thought to be involved. Rarely, cytokine storm can cause macrophage activation syndrome (MAS).
• Main symptoms: Recurrent high fever (often ≥39°C), characteristic skin rash (a transient pink rash that occurs together with fever), arthralgia and arthritis (commonly affecting the knees and wrists), myalgia, sore throat, hepatomegaly and abnormal liver function, increased blood cell counts, and elevated acute-phase reactants (CRP and ESR). Rheumatoid factor (RF) and antinuclear antibodies (ANA) are usually negative or weakly positive. Abnormally high ferritin levels (provided data: 3,000–10,000 ng/dL) are characteristic.

2) Treatment Methods and Precautions

• First-line treatment (depending on symptoms and severity):
  • Nonsteroidal anti-inflammatory drugs (NSAIDs): For mild disease or relief of early symptoms.
  • Systemic glucocorticoids (steroids): Used at a high dose for a short period in cases of moderate or more severe systemic symptoms or severe arthritis, followed by gradual dose reduction.
• In cases of chronic disease, steroid dependence, or risk of joint damage:
  • Disease-modifying antirheumatic drugs (DMARDs): Such as methotrexate, for reducing steroid use and preventing joint destruction.
  • Biologic agents (for refractory or recurrent cases): IL‑1 inhibitors (anakinra, canakinumab) and an IL‑6 inhibitor (tocilizumab) are effective.
• If macrophage activation syndrome (MAS) is suspected:
  • Immediate hospitalization and high-dose steroids; immunosuppressants (such as cyclosporine); and, if necessary, plasma exchange and other treatments should be considered.
• Other: Antibiotics are ineffective after infection has been ruled out (bacterial cultures are often negative). With long-term steroid use, management of osteoporosis, infection, and metabolic adverse effects (such as elevated blood glucose and hypertension) is necessary.
• Monitoring: Regular follow-up of CBC, CRP/ESR, liver function (AST/ALT), ferritin, kidney function, and other parameters. When using biologic agents, vaccinations and active infections should be checked (some live vaccines are contraindicated during biologic therapy).

3) Checklist Before an Outpatient Visit (Examples of Items to Bring and Records to Keep)

• Items/materials to bring: A list of all medications and supplements currently being taken (including dosage and duration of use), recent test results (blood tests: CBC, CRP, ESR, ferritin, LFT, etc.), previous medical and hospitalization records, and records of previously used anti-inflammatory drugs, steroids, and biologic agents.
• Symptom-related records: A body temperature diary (timing and pattern of fever), photos of the rash (for comparison when fever is present and absent), the location, intensity, and duration of joint pain (pain diary), and the timing and triggers of symptoms (such as exposure to infections).
• Lifestyle and other information: Smoking, alcohol use, occupation (whether there is exposure to infection), pregnancy plans (for women), and vaccination history.

4) Examples of General Questions to Ask the Doctor

• What are the expected effects and common side effects of this treatment (specific medication)?
• What plan should be made to reduce or discontinue steroids?
• What are the criteria for starting a biologic agent? How are side effects and infection risks managed?
• What is the usual course and prognosis of this disease (possibility of a self-limited course, intermittent relapses, or chronic progression)?
• If pregnancy or breastfeeding is planned, how should medication selection and timing be adjusted?

5) Examples of Disease-Specific Questions

• How should my serum ferritin level (most recent level) be interpreted? How frequently should it be measured to assess treatment response?
• Despite recurrent fever and arthritis, what are the specific criteria for switching to a biologic agent rather than methotrexate (e.g., steroid dependence, signs of joint destruction)?

Additional (Emergency Warning Signs): If persistent or high fever worsens, or if altered consciousness, difficulty breathing, bleeding or bruising, a sudden drop in blood pressure, or other symptoms occur, immediate evaluation in an emergency room is necessary (possible complications (MAS) or sepsis).