Overview
Adult-onset Still disease (AOSD) is a rare inflammatory disorder that affects the whole body. It is sometimes called Adult Still disease and is considered the adult form of a childhood condition known as systemic juvenile idiopathic arthritis. The disease causes episodes of high spiking fevers (often 102°F or higher), a salmon-pink skin rash that comes and goes, and painful, swollen joints. These flare-ups can last for weeks or months. The inflammation can also affect internal organs, including the liver, spleen, lymph nodes, heart, and lungs. In some people, the disease follows a single episode and then goes away, while in others it becomes chronic and leads to long-term joint damage. The exact cause of AOSD is not fully understood. It is thought to involve an overactive immune system, where the body's defense mechanisms mistakenly attack its own tissues. Certain immune signaling molecules, especially interleukin-1 (IL-1), interleukin-6 (IL-6), and interleukin-18 (IL-18), are found at very high levels during flares. A serious and potentially life-threatening complication called macrophage activation syndrome (MAS) can occur, where the immune system becomes dangerously overactive. Treatment focuses on controlling inflammation and preventing organ damage. Nonsteroidal anti-inflammatory drugs (NSAIDs) may help mild cases, but most patients need corticosteroids like prednisone. For patients who do not respond well or who need to reduce steroid use, biologic medications that block specific immune signals — such as anakinra, canakinumab, and tocilizumab — have become important treatment options. With proper treatment, many people with AOSD can achieve good disease control and maintain a good quality of life.
Also known as:
Key symptoms:
High spiking fevers, often occurring once or twice dailySalmon-pink skin rash that appears with fever and fades when fever dropsJoint pain and swelling, especially in the knees, wrists, and anklesSevere sore throatSwollen lymph nodesEnlarged liver or spleenMuscle pain and body achesExtreme fatigue and feeling unwellWeight lossChest pain from inflammation around the heart or lungsAbdominal painVery high white blood cell countElevated ferritin levels in the bloodJoint stiffness, especially in the morning
Clinical phenotype terms (50)— hover any for plain English
Sporadic
Usually appears on its own, not inherited from a parent
Adult
Begins in adulthood (age 18 or older)
FDA & Trial Timeline
8 eventsNovartis Pharmaceuticals — PHASE2
Ruijin Hospital
Ruijin Hospital — NA
Swedish Orphan Biovitrum — PHASE3
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Institut National de la Santé Et de la Recherche Médicale, France
Brugmann University Hospital
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
1 availableILARIS
indicated for the treatment of active Still's Disease, including Adult-Onset Still's Disease (AOSD) and Systemic Juvenile Idiopathic Arthritis (SJIA) in patients 2 years of age and older
Rare Disease Specialist
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Adult-onset Still disease.
Community
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Start the conversation →Latest news about Adult-onset Still disease
Disease timeline:
New recruiting trial: Glycosylated Ferritin in Macrophagic Activation Syndromes
A new clinical trial is recruiting patients for Adult-onset Still disease
New recruiting trial: Rheumatology Patient Registry and Biorepository
A new clinical trial is recruiting patients for Adult-onset Still disease
New recruiting trial: A Phase II Trial to Evaluate the Clinical Efficacy, Safety and Tolerability of MAS825 in Pediatric and Adult Participants With Still's Disease
A new clinical trial is recruiting patients for Adult-onset Still disease
New recruiting trial: Natural History, Genetics, and Pathophysiology of Systemic Juvenile Idiopathic Arthritis, Adult-Onset Still's Disease, and Related Conditions
A new clinical trial is recruiting patients for Adult-onset Still disease
New recruiting trial: Acostill ( RaDiCo Cohort) (RaDiCo Acostill)
A new clinical trial is recruiting patients for Adult-onset Still disease
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.What type of Adult-onset Still disease do I have — is it likely to be a single episode, recurring, or chronic?,What are the signs of macrophage activation syndrome, and what should I do if I suspect it?,Which medications do you recommend, and what are the short-term and long-term side effects?,How often will I need blood tests and follow-up appointments?,Are there biologic therapies that might help me reduce or stop corticosteroids?,What lifestyle changes can help me manage fatigue and joint symptoms?,Should I see any other specialists, and are there clinical trials I might be eligible for?
Common questions about Adult-onset Still disease
What is Adult-onset Still disease?
Adult-onset Still disease (AOSD) is a rare inflammatory disorder that affects the whole body. It is sometimes called Adult Still disease and is considered the adult form of a childhood condition known as systemic juvenile idiopathic arthritis. The disease causes episodes of high spiking fevers (often 102°F or higher), a salmon-pink skin rash that comes and goes, and painful, swollen joints. These flare-ups can last for weeks or months. The inflammation can also affect internal organs, including the liver, spleen, lymph nodes, heart, and lungs. In some people, the disease follows a single episo
How is Adult-onset Still disease inherited?
Adult-onset Still disease follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Adult-onset Still disease typically begin?
Typical onset of Adult-onset Still disease is adult. Age of onset can vary across affected individuals.
Are there clinical trials for Adult-onset Still disease?
Yes — 6 recruiting clinical trials are currently listed for Adult-onset Still disease on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Adult-onset Still disease?
25 specialists and care centers treating Adult-onset Still disease are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.