Painful subcutaneous edema is associated with early age at disease onset in Immunoglobulin A vasculitis patients: A multicenter study.

OBJECTIVE: To evaluate the risk factors associated with the presence of Painful Subcutaneous Edema (PSE) in children and adolescents with Immunoglobulin A Vasculitis (IgAV). METHODS: A multicenter study evaluated 686 patients (≤ 18 years-old) at first 3-months after diagnosis. IgAV patients with PSE were compared to those without PSE. RESULTS: PSE was found in 219/686 (31.9 %). The sites were lower limbs 192/215 (89.3 %) and upper limbs 85/215 (39.5 %). Persistent PSE (≥ 6-weeks of duration) was found in 4/215 (2 %), and recurrent PSE was found in 7/217 (3 %). The median age at diagnosis was significantly lower in PSE patients compared to those without [5.0 (3.4) vs. 6.3 (4.3) years, p = 0.001]. Increased CRP was significantly higher in IgAV with PSE compared to without PSE (52.6 % vs. 41.1 %, p = 0.03), likewise thrombocytosis (> 400.000 mm3) (43.8 % vs. 35.1 %, p = 0.04). Although associated with higher inflammatory markers, PSE was not linked to more severe outcomes. Logistic regression demonstrated that age at diagnosis was inversely associated with PSE (OR = 0.986; 95 % CI 0.981‒0.992; p < 0.001). CONCLUSION: PSE occurred in approximately one-third-of IgAV patients at disease onset and was diagnosed predominantly at an early age, with a more inflammatory presentation at onset. However, in spite of the higher levels of inflammatory markers, PSE was not linked to more severe outcomes.