- Prolonged pyrexia (see below)
- Intermittent characteristic rash (see below)
- Raised CRP, ESR, ferritin (esp over 1000 – also haemophagocytic syndromes, haemochromatosis, liver disorders, malignancy)
- Poor response to IVIG (cf Kawasakis)
- Leucocytosis (neutrophilia, can be leukaemoid)
- Generalised lymphadenopathy
Can be systemically very unwell and potentially life threatening complications may occur early in the disease course (eg pericarditis, macrophage activation syndrome or HLH, sepsis). See the Big Sick film from Netflix. Start high dose corticosteroids after careful exclusion of other diagnoses, especially infection, Kawasaki disease, and malignancy – difficult when arthritis is absent! But maybe you have to look harder…
Systemic features may predate the arthritis by several weeks and occasionally longer. Typically involves small joints of the hands and wrists, ankles, hips, knees, and cervical spine – about 30% ultimately develop severe polyarthritis.
There are no pathognomic tests or agreed diagnostic criteria for SOJIA! Classic features:
- quotidian (=daily) evening spiking temperature, that returns to or falls below baseline by the morning.
- Rash is faint, salmon pink maculopapular, most obvious during pyrexia. Usually not on the face so easily missed – typically on the trunk, inner thigh and axillae, especially on areas of trauma or pressure (Koebner phenomenon).
Treat with IV methylprednisolone pulses (30mg/kg over 4 hours, max 1g, once daily for 3 days) and ibuprofen (seems better than piroxicam for SOJIA!). Oral prednisolone may then be used while methotrexate is introduced.