Cardiac involvement in severe cutaneous adverse reactions: a Retrospective Observational Cohort Study of DRESS and SJS/TEN at a major Australian tertiary hospital

Background Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), Stevens-Johnson Syndrome (SJS), and Toxic Epidermal Necrolysis (TEN) are life-threatening adverse medication reactions, often with multiorgan involvement. Cardiac involvement in these conditions has not been well-characterised. Objectives To evaluate the prevalence, clinical spectrum, and outcomes of cardiac involvement in patients diagnosed with DRESS and SJS/TEN. Methods A single-centre retrospective cohort study was conducted. DRESS and SJS/TEN patients between January 2014 and January 2024 were identified through the hospital adverse drug reaction database. Cardiac involvement was defined as the presence of cardiac symptoms accompanied by any new abnormality detected on electrocardiograms, cardiac biomarkers, and/or cardiac imaging during admission. Results 58 patients were included: 79 with DRESS and 79 with SJS/TEN. Cardiac involvement was identified in 15.2% of DRESS and 6.3% of SJS/TEN cases. Cardiovascular risk factors were prevalent across both conditions with hypertension being the most common. Cardiac symptoms were reported in up to 20% with dyspnoea being the most frequent. Of those who had cardiac investigations, new electrocardiographic abnormalities were detected in up to 42% of patients. ICU admissions and mortality were higher in SJS/TEN but there was no mortality attributable to cardiac involvement. Antibiotics were the most frequently implicated medications in both groups. In DRESS subgroup analysis, cardiac involvement was associated with higher rates of renal involvement (100% vs 64%, p = 0.014) and ICU admission (67% vs 34%, OR = 3.83, 95% CI 1.04–14.07, p = 0.043), but was less common with antibiotics exposure as a cause of DRESS (58% vs 84%, OR = 0.28, 95% CI 0.07– 1.03, p = 0.055). Conclusion Cardiac involvement is an under-recognised but clinically important feature of DRESS and SJS/TEN. Findings highlight the contribution of cardiac dysfunction to morbidity and support routine cardiac assessment in patients with SCAR. Larger prospective studies and national drug reaction registries are needed to better define burden and guide care.