A child has daily fever spikes, a rash that comes and goes, and joint pain. An adult develops a remarkably similar illness. For many years, they would usually receive different names: systemic juvenile idiopathic arthritis in childhood and adult-onset Still’s disease later in life.
Those names still appear in medical records, research, and insurance paperwork. Increasingly, clinicians understand them as part of the same disease spectrum. The 2024 EULAR/PReS recommendations bring care across ages together under the name Still’s disease.
More than arthritis
Still’s disease causes inflammation throughout the body. Fever, a transient rash, joint symptoms, and marked fatigue are common parts of the picture. Some people have a sore throat, enlarged lymph nodes, or inflammation involving the liver or the linings around the heart or lungs. Joint inflammation may not be the most obvious feature at the start.
Descriptions often mention a salmon-colored rash, but a rash can look different across skin tones and some people have less typical skin findings. Photographs taken when it appears can be useful to the clinical team.
There is no single test that proves it
Blood tests may show high inflammatory markers, increased white blood cells, or high ferritin, a protein involved in iron storage that also rises with inflammation. None of those findings is specific to Still’s disease. Infection, cancer, and other inflammatory conditions can produce overlapping features.
The diagnosis depends on the overall pattern and a careful evaluation of alternatives. A high ferritin result alone cannot establish the diagnosis, and a label should be reconsidered when new findings do not fit.
Treatment aims for a life with less inflammation
The goal is more than lowering the temperature for a day. It is to control inflammation, protect organs and joints, restore function, and reduce treatment harms. The current recommendations favor early use of medicines targeting IL-1 or IL-6, key inflammatory signals, with glucocorticoids used for as short a time as the situation allows.
The right medicine depends on the person’s illness, complications, prior response, access, and safety considerations. These treatments require monitoring for infection and other adverse effects. Do not abruptly stop glucocorticoids or change a biologic schedule without a plan from your team.
At follow-up, discuss fatigue, pain, school or work, sleep, and the activities that matter to you. Improvement in a blood test is welcome, but daily function is part of the treatment goal too.
Know about macrophage activation syndrome
Macrophage activation syndrome, or MAS, is a serious complication in which inflammation becomes overwhelming and can injure multiple organs. It needs urgent medical assessment and usually hospital treatment. It can occur during Still’s disease, including in someone already receiving treatment.
Ask your team for an individual emergency plan. A fever pattern that changes or persists, rapid worsening, unusual bruising or bleeding, confusion, severe drowsiness, breathing difficulty, or fainting should not be managed simply as another usual flare. Seek emergency care for severe symptoms. Infection can cause similar problems and can also trigger MAS; patients should not have to distinguish these possibilities at home.
Questions worth bringing to the next appointment
- What findings support my diagnosis, and what alternatives have been considered?
- What would count as good disease control for me?
- How will we reduce glucocorticoid exposure safely?
- Which new symptoms require an urgent call or emergency care?
- What is the plan for monitoring treatment and preventing infections?
Different names and age cutoffs can make this disease confusing. A shared treatment plan helps keep the focus on the same goals: controlling inflammation and helping a person return to their life.
Keep reading
Sources and further reading
- EULAR/PReS recommendations for Still’s disease, including systemic JIA and adult-onset Still’s disease (2024)
- EULAR/ACR points to consider for early suspected HLH/MAS (published 2023)
Adapted from Jonathan S. Hausmann’s presentation, “The Management of Still’s and Macrophage Activation Syndrome,” with references and terminology updated for this article. Individual patient cases and slide images have not been reproduced.
This article provides general education, not a diagnosis or an individual treatment plan. Discuss personal medical decisions with your care team.