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

## TL;DR

Painful subcutaneous edema occurs in about a third of IgAV patients, mostly in children, and is linked to younger age at diagnosis.

## Contribution

The study identifies early age at diagnosis as a novel risk factor for painful subcutaneous edema in IgAV patients.

## Key findings

- Painful subcutaneous edema was found in 31.9% of IgAV patients at disease onset.
- PSE was predominantly observed in younger patients, with a significantly lower median age at diagnosis.
- Despite higher inflammatory markers, PSE was not associated with more severe disease outcomes.

## Abstract

•PSE occurred in approximately one-third of IgAV patients at disease onset.•IgAV painful subcutaneous edema was mainly located on the lower and upper limbs.•IgAV painful subcutaneous edema was identified predominantly at an early age.

PSE occurred in approximately one-third of IgAV patients at disease onset.

IgAV painful subcutaneous edema was mainly located on the lower and upper limbs.

IgAV painful subcutaneous edema was identified predominantly at an early age.

To evaluate the risk factors associated with the presence of Painful Subcutaneous Edema (PSE) in children and adolescents with Immunoglobulin A Vasculitis (IgAV).

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.

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).

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.