Synopsis
Recognise the fever, rash, arthritis and systemic pattern of adult-onset Still disease, exclude infection and malignancy, identify macrophage activation syndrome, and escalate cytokine-directed therapy with specialist oversight.
- Adult-onset Still disease is a diagnosis of pattern and exclusion: high spiking fever, evanescent salmon-pink rash, inflammatory arthritis, neutrophilia, sore throat, lymphadenopathy and liver inflammation are typical clues.
- Rash may appear with fever and fade before examination; ask for photographs and examine during a temperature spike without relying on colour description alone across skin tones.
- Marked ferritin supports intense inflammation but is not specific; sepsis, liver injury, malignancy and macrophage activation also raise it.
- RF and ANA are usually absent but negative serology does not prove Still disease.
- Obtain repeated cultures, infection imaging and malignancy-directed assessment before major immunosuppression, guided by the exposure and organ phenotype.
- Falling platelets, fibrinogen or ESR despite ongoing fever, rising triglycerides, liver injury, coagulopathy and neurological change suggests macrophage activation syndrome.
- Once Still disease is established, introduce IL-1 or IL-6 inhibition as early as possible through specialist care; use systemic glucocorticoids briefly as a bridge or for severe organ disease rather than allowing prolonged steroid dependence.
- Track systemic and articular phenotypes separately because some patients evolve from febrile disease into chronic destructive arthritis.
Key red flags
Persistent fever with falling cell counts, fibrinogen, coagulopathy, hepatic or neurological deterioration and rising ferritin is an immediate inflammatory emergency.
Positive cultures, focal imaging, clonal blood or tissue findings or discordant response redirects diagnosis and prevents hazardous escalation of immunosuppression.
Investigation priorities
Characterise systemic inflammation and detect evolving macrophage activation syndrome.
Management branches
Spiking fever, rash, inflammatory joints and high inflammatory markers suggest Still disease without current shock.
- Obtain repeated cultures, infection and travel testing, full blood and liver assessment and imaging guided by nodes, organs and constitutional features.
- Seek rheumatology and haematology input early and arrange tissue sampling when malignancy or unusual infection remains plausible.
- Begin specialist anti-inflammatory treatment only with an explicit parallel plan for pending cultures, organ monitoring and reassessment of the diagnosis.
Key medicines
PrednisoloneA common specialist initial range is 0.5–1 mg/kg orally once daily for significant systemic disease, followed by a response-led taper and steroid-sparing plan.Continue parallel infection assessment and monitor glucose, blood pressure, mood, eyes and bone. Use the shortest effective course, prevent opportunistic infection when the regimen warrants it and never stop established prolonged therapy abruptly.
AnakinraAt body weight 50 kg or more, use 100 mg subcutaneously once daily; below 50 kg, start 1–2 mg/kg/day. In severe renal impairment with creatinine clearance below 30 mL/min, consider dosing every other day.Do not start during active serious infection and do not give live vaccines concurrently. Check neutrophils before treatment, monthly for six months and quarterly thereafter; monitor liver tests and injection reactions. Product information does not recommend routine use in pregnancy, so use specialist reproductive planning and document later-pregnancy exposure for the infant-vaccine team.