CHRONIC spontaneous urticaria (CSU) in systemic lupus erythematosus (SLE) was not linked to higher disease activity, but was associated with distinct clinical and laboratory risk factors.
Systemic Lupus Erythematosus with Chronic Spontaneous Urticaria
A multicenter retrospective study evaluated epidemiologic features of SLE comorbid with CSU, the relationship between CSU onset and lupus disease activity, and potential risk factors for this comorbidity pattern. Investigators analyzed 40 patients with SLE and CSU alongside 160 age matched and sex matched SLE controls without CSU.
To assess whether CSU tracked with lupus activity, the authors compared Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores before and after CSU onset within the SLE-CSU cohort using a Wilcoxon signed rank test. They also compared disease activity at SLE onset between groups using the Mann-Whitney U test, and evaluated differences in activity grading, manifestations, laboratory findings, and treatments using χ2 testing. Univariate and multivariate logistic regression were used to identify independent predictors of CSU occurrence in SLE.
Chronic Spontaneous Urticaria Did Not Signal Higher Lupus Activity
Within the SLE-CSU group, CSU occurrence did not correspond to an increase in SLEDAI scores, suggesting that CSU was not a reliable marker of heightened systemic lupus erythematosus activity in this cohort. The authors emphasize that clinicians should avoid assuming flare level disease based on CSU alone, and instead interpret urticaria in the broader context of clinical findings and laboratory data.
Risk Factors Linked to SLE With CSU
In univariate comparisons, several variables differed between systemic lupus erythematosus patients with CSU and those without CSU, including cylindruria, elevated IgM, elevated IgA, elevated IgG, serositis, mucosal ulcers, and anti-Pm-Scl antibodies. In multivariate analysis, four factors remained independently associated with CSU occurrence in systemic lupus erythematosus: cylindruria (OR 6.152), elevated IgA (OR 7.598), elevated IgG (OR 3.252), and mucosal ulcers (OR 3.838).
The findings suggest that SLE with CSU may reflect specific comorbidity patterns and immune laboratory profiles rather than higher global disease activity. In practice, systemic lupus erythematosus patients presenting with CSU may warrant targeted evaluation for these associated features, particularly urinary findings, immunoglobulin elevations, and mucosal involvement.
Reference: Zeng X et al. Systemic lupus erythematosus comorbid with chronic spontaneous urticaria: a multicentre retrospective study. Lupus Sci Med. 2025;12(2):e001677.
