Stevens-Johnson syndrome and toxic epidermal necrolysis in Hong Kong.

INTRODUCTION: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) [hereafter, SJS/TEN] are uncommon but severe mucocutaneous reactions. Although they have been described in many populations worldwide, data from Hong Kong are limited. Here, we explored the epidemiology, disease characteristics, aetiology, morbidity, and mortality of SJS/TEN in Hong Kong. METHODS: This retrospective cohort study included all hospitalised patients who had been diagnosed with SJS/TEN in Prince of Wales Hospital from 1 January 2004 to 31 December 2020. RESULTS: There were 125 cases of SJS/TEN during the 17-year study period. The annual incidence was 5.07 cases per million. The mean age at onset was 51.4 years. The mean maximal body surface area of epidermal detachment was 23%. Overall, patients in 32% of cases required burns unit or intensive care unit admission. Half of the cases involved concomitant sepsis, and 23.2% of cases resulted in multiorgan failure or disseminated intravascular coagulation. The mean length of stay was 23.9 days. The cause of SJS/TEN was attributed to a drug in 91.9% of cases, including 84.2% that involved anticonvulsants, allopurinol, antibiotics, or analgesics. In most cases, patients received treatment comprising either best supportive care alone (35.2%) or combined with intravenous immunoglobulin (43.2%). The in-hospital mortality rate was 21.6%. Major causes of death were multiorgan failure and/or fulminant sepsis (81.5%). CONCLUSION: This study showed that SJS/TEN are uncommon in Hong Kong but can cause substantial morbidity and mortality. Early recognition, prompt withdrawal of offending agents, and multidisciplinary supportive management are essential for improving clinical outcomes.

The risk of anti-osteoporotic agent-induced severe cutaneous adverse drug reactions and their association with HLA.

BACKGROUND: There is increasing use of anti-osteoporotic agents (AOA) worldwide for prevention or management of patients with osteoporosis. However, there have been reports of severe cutaneous adverse reactions (SCAR) induced by AOA. A recent study showed weak association between HLA and strontium ranelate (SR)-SCAR. OBJECTIVE: To characterize patients with AOA-SCAR and investigate the HLA association and utility of in vitro diagnostic methods. METHODS: We enrolled 16 cases with AOA-cutaneous adverse drug reactions (cADR), including SCAR (n = 10: 8 with Stevens-Johnson syndrome [SJS] and 2 with drug rash with eosinophilia and systemic symptoms [DRESS]) and maculopapular exanthema (MPE) (n = 6) from Taiwan and Hong Kong. We analysed the clinical characteristics, outcomes, HLA alleles and in vitro testing of AOA-SCAR, and tolerability to alternative drugs. We further performed literature review and meta-analysis on the HLA association of AOA-SCAR. RESULTS: Our data showed strontium ranelate is the most common causality of AOA-SCAR in Asian populations. There was no cross-hypersensitivity of SR-SCAR with other AOA. HLA genotyping showed that SR-SJS was most significantly associated with HLA-A*33:03 (Pc = 5.17 × 10-3 , OR: 25.97, 95% CI: 3.08-219.33). Meta-analysis showed that HLA-A*33:03 was associated with SR-SJS (P = 5.01 × 10-5 ; sensitivity: 85.7%) in Asians. The sensitivity of lymphocyte activation test (LAT) for identifying the culprit drug of SR-SJS was 83.3%. CONCLUSIONS: Strontium ranelate is identified as the most notorious AOA associated with SCAR. The HLA-A*33:03 genetic allele and LAT testing may add benefits to the diagnosis of SR-SCAR in patients whose reaction developed while taking multiple drugs.