Clinical and Epidemiological Characteristics of Severe Cutaneous Adverse Drug Reactions at the Kenyatta National Hospital

Abstract

Severe Cutaneous Adverse Reactions (SCARs) are rare but potentially fatal drug-induced skin reactions, including Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN), Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), and others. They pose a significant burden, especially in resource-constrained settings like Kenya, where data on their epidemiology and risk factors remain limited. This study aimed to describe the clinical and epidemiological characteristics of SCARs in patients at Kenyatta National Hospital (KNH), contributing to pharmacovigilance efforts and drug safety profiles in Kenya. The study's broad objective is to describe the clinical and epidemiological characteristics of patients admitted with SCARs. Specifically, it aimed to determine the clinical phenotypes of SCARs, identify their epidemiological characteristics, and evaluate causality in SCAR cases at KNH. A hybrid cohort design was employed, comprising retrospective and prospective data collection. A total of 102 patients were recruited via consecutive sampling. Data were gathered through file reviews, clinical examinations, and interviews, focusing on demographics, clinical features, etiologies, and co-morbidities. Statistical analyses, including chi-square and Kruskal-Wallis tests, were conducted using SPSS, with ethical approval from the KNH-UoN ERC. SJS/TEN was the most common phenotype (55.9%), followed by Drug-Induced Erythroderma (17.6%) and Drug-Induced Erythema Multiforme (11.8%). Participants had a mean age of 29.4 years, with a slight female predominance (51%). Antimicrobials (60.8%) and anticonvulsants (13.5%) were the most implicated drug classes, with co-trimoxazole, ceftriaxone and carbamazepine identified as common culprits. HIV was the most prevalent comorbidity (23.9%). Significant organ involvement included acute kidney injury (11.8%) and drug-induced liver injury (8.8%). Eosinophilia was associated with DIE (72.2%). Overall in-hospital mortality was 16.8% with the highest case fatality rate recorded in SJS/TEN (21.05%). SCARs in the Kenyan population were characterized by a younger age distribution, predominance of SJS/TEN, and a strong association with antimicrobials and anticonvulsants as the primary culprits. The high rates of organ involvement and in-hospital mortality, with acute kidney injury emerging as a key predictor of mortality, underscore the severity of these reactions. These findings highlight the need for early diagnosis, strengthened pharmacovigilance, and targeted interventions to improve patient outcomes. Future research should explore pharmacogenetics, long-term sequelae of SCARs, and the role of HIV in these severe reactions.