Impact of skin disease, interstitial lung disease, and IVIG use on in-hospital mortality in dermatomyositis: A retrospective case control study

Summary: Abstract Body: Background: Dermatomyositis(DM) is an autoimmune disorder characterized by muscle inflammation, distinctive skin rashes, and comorbidities such as interstitial lung disease(ILD) and malignancy. Hospitalized DM patients face significant morbidity and mortality, with infection previously identified as a leading cause of death. However, specific factors influencing in-hospital mortality at admission remain poorly defined. Methods: We conducted a retrospective review of 153 adult DM patients admitted to Johns Hopkins Medicine(October 2013–February 2024). Data collected included demographics, disease characteristics, and hospitalization outcomes. Deceased patients were compared to survivors using t-tests, chi-squared tests, and multivariable logistic regression. Results: Among 153 patients (mean age 56.5 years, 73.9% female), 10.5% died during hospitalization. Compared to survivors, deceased patients had a shorter duration of DM (4.08 vs. 7.57 years, p=0.023) and were less likely to be on IVIG at admission (31.3% vs. 61.3%, p=0.041). They were significantly more likely to present with active skin disease (81.3% vs. 34.3%, p<0.001), ILD (87.5% vs. 41.6%, p=0.001), and concurrent rash and ILD (68.8% vs. 11.7%, p<0.001). In adjusted logistic regression, active skin disease (OR 9.71, 95% CI 2.33-56.64, p<0.01) and ILD (OR 8.01, 95% CI 2.04-46.80, p<0.01) remained significant predictors of mortality, while IVIG was protective (OR 0.28, 95% CI 0.09-0.89, p=0.032). All deceased patients experienced respiratory failure, predominantly due to ILD exacerbations (56.3%) or infection (37.5%). Conclusions: Our study is the first to highlight active skin disease as a critical predictor of in-hospital mortality in DM, likely reflecting heightened systemic disease burden. We found that IVIG may confer a protective effect, though disease severity was not accounted for. Clinicians should recognize the association between active skin disease and heightened mortality risk in hospitalized DM patients to guide appropriate management. Anjana Srikumar¹, Maria Kaltchenko¹, Keon Niknejad¹, Jun Kang¹ 1. Department of Dermatology, Johns Hopkins Medicine, Baltimore, MD, United States. Clinical Research: Epidemiology and Observational Research