Clinical characteristics and vascular involvement of Takayasu arteritis versus Kawasaki disease in infants and young children.

backgroundChildhood-onset Takayasu arteritis (c-TAK) in infants and young children often presents with systemic inflammation rather than ischemic symptoms, and its clinical features overlap with intravenous immunoglobulin (IVIG)-resistant Kawasaki disease (KD). To aid in early differentiation, this study compared clinical characteristics and vascular involvement between c-TAK and IVIG-resistant KD in infants and young children.

methodsThis single-center retrospective cohort study included patients under three years old diagnosed with c-TAK or IVIG-resistant KD between June, 2016, and December, 2025. Demographics, clinical presentation, laboratory findings, vascular involvement, immunotherapy, and outcomes were compared between groups.

resultsA total of 144 infants and young children were enrolled, including 43 with c-TAK and 101 with IVIG-resistant KD. Compared to the IVIG-resistant KD group, the c-TAK group had a significantly higher proportion of infants (85.7% vs. 29.7%) and females (67.4% vs. 32.7%), longer fever duration (18 [9, 26] vs. 11 [9, 13] days), higher lymphocyte counts (7.09 [5.58, 9.02] vs. 2.92 [2.18, 3.91] × 10⁹/L), and more medium-to-giant coronary artery aneurysms (CAAs; 48.8% vs. 18.8%; all P < 0.001). At the baseline, 76.7% of c-TAK patients received IVIG but experienced recurrent fever. The imaging features in the c-TAK group included vessel wall thickening (95.3%), dilation (79.1%), and stenosis (41.9%). The most commonly involved arteries were the carotid (79.1%), abdominal aorta (69.8%), subclavian (67.4%), and coronary artery (67.4%). Conversely, the IVIG-resistant KD group mainly exhibited CAAs (29.7%). The median follow-up duration was comparable between the two groups (21.0 [11.8, 45.5] vs. 18.0 [12.0, 36.0] months, P = 0.952). By the final follow-up, vascular imaging abnormalities completely resolved in 10.3% of c-TAK patients and 96.9% of IVIG-resistant KD patients.

conclusionIn young children, particularly female infants, who present with prolonged fever and a poor response to IVIG, c-TAK should be considered as an important differential diagnosis alongside IVIG-resistant KD. The distribution of vascular involvement, detailed imaging characteristics and regular follow-up may be helpful for the differential diagnosis of these two diseases.