Drug-induced Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and SJS-TEN overlap: A multicentric retrospective study

Background : Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare immune-mediated severe cutaneous adverse reactions with incidence rate of 0.05 to 2 persons per million populations per year. Drugs are the most commonly implicated in 95% of cases.
Aims : To audit the causative drugs, clinical outcome, and cost of management in SJS, TEN, and SJS-TEN overlap. Setting and Design: Tertiary care hospitals-based multicentric retrospective study (case series).
Materials and Methods : Indoor case papers of SJS, TEN, and SJS-TEN overlap admitted between January 2006 and December 2009 in four tertiary care hospitals of Gujarat were scrutinized. Data were collected for demographic information, causative drugs, investigations, treatment given, duration of hospital stay, time interval between onset of symptoms and drug intake, clinical outcome, and complications. Data were analyzed to find out proportion of individual drugs responsible, major complications, and clinical outcome in SJS, TEN, and SJS-TEN overlap. Total cost of management was calculated by using cost of drugs, investigations, and consumables used during entire hospital stay. Statistical Analysis : One-way Analysis of Variance followed by Tukey-Kramer multiple comparison test was used for comparison of incubation period, duration of hospital stay, and cost of management.
Results : Antimicrobials (50%), nonsteroidal anti-inflammatory drugs (22.41%), and antiseizure drugs (18.96%) were the most commonly associated groups. Nevirapine (28.12%) was the most common drug. Antiseizure drugs were more often associated with serious form of adverse reaction (TEN: 81.8%) than other drugs. Duration of hospital stay (20.6 vs 9.7 days) and cost of management (Rs 7 910/- vs Rs 2 460/-) were significantly higher in TEN than SJS (P=0.020 and P<0.001, respectively). Time duration between drug intake and onset of symptoms (17.7 vs 27.5 days) was nonsignificantly lower in TEN as compared with SJS. Secondary infection (28.12%) was the most common complication noted. Mortality rate was 15.6% among all cases; 9% in SJS and 26.7% in TEN.
Conclusion : Antimicrobial drugs are the most commonly implicated drugs and cost of managing these adverse drug reactions is higher than other serious ADRs.

Keywords
Adverse drug reaction, Stevens-Johnson syndrome, toxic epidermal necrolysis