Systemic autoinflammatory diseases (SAIDs) are genetic conditions that cause innate immune system hyperactivation, manifesting as unprovoked inflammation. The number of children with SAIDs in Australia is unknown. There is often limited awareness and few diagnostic tools.
We set out to characterise the state of care of SAID patients at Queensland Children’s Hospital between 2016 and 2025.
Retrospective chart analysis identified 189 children (0–18 y). Subset analysis of 55 active patients revealed an age of onset 6 m–15 y. Commonest symptoms included periodic fevers (71%) and abdominal and joint symptoms (50%). Most patients underwent blood count (100%) and inflammatory marker (98%) investigations, but only 21% had urinary tests. Genetic testing was performed in 61%; only 14% had a positive result. Retrospective clinical scoring was conducted using validated consensus protocols. Periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAFA) scoring was useful but lacked specificity. Familial mediterranean fever (FMF) scoring was aided by pathognomonic serositis and ethnicity. Mevalonate kinase deficiency criteria had limited specificity, but the presence of specific triggers was helpful. Cryopyrin-associated periodic syndrome (CAPS) criteria were robust, particularly when urticaria, sensorineural hearing loss, and central nervous system symptoms were combined. TNF receptor-associated periodic syndrome scoring performed poorly as symptoms were non-specific. Periorbital oedema while pathognomonic was very rare. IFN-opathies scoring performed well due to rare manifestations (i.e., vasculopathy, lipodystrophy, pulmonary interstitial lung disease). Most patients were affected by undifferentiated SAID (61%); PFAPA was diagnosed in 12%. CAPS and CAPS-like conditions were present in 8%. Other conditions (adenosine deaminase 2 deficiency, FMF, STING associated vasculopathy with onset on infancy, NLRP1, A20 haploinsufficiency, and Aicardi-Goutieres syndrome) were less common. Most patients were treated with corticosteroids (47%). Anakinra was used in 15%, JAK inhibitor and colchicine in 8–12%, and TNF inhibitors in 10%.
SAID presentations were heterogenous, undifferentiated, and had a broad age of onset. Clinical classification criteria tools were useful but lacked specificity. Genetic yield was low (14%). Trials of immune-modulatory medications were common. Increasing expertise and developing a model of care are likely to improve these challenges and improve patient management.
