**2. Epidemiology of severe cutaneous adverse reactions (SCARs)**

The skin is the most common and easily visible body part that manifest symptom of adverse drug reactions [6]. Adverse Drug Reactions (ADRs) contribute up to 7% of the hospital admissions of which cutaneous ADRs alone contribute to 2–3% of the overall hospitalizations [7, 8]. Few of these cutaneous adverse drug reactions have disabling sequelae or can be life-threatening. The incidence of fatalities among inpatients due to systemic and cutaneous adverse drug reactions reported ranges between 0.1% to 0.3%. However, the mortality rates for SJS/TEN are approximately 5–10%, 30–50% in TEN, 10% in DRESS, and the common leading culprit drugs associated with SCARs, around the world are antibiotics, anti-epileptics, allopurinol, Non-steroidal anti-inflammatory drugs (NSAIDS), and antiretrovirals [9–11]. Incidence rates of SJS/TEN range from 1.4–12.7/million person-years in different studies [12–14]. A Nationwide Korean Study of Severe Cutaneous Adverse Reactions by Kang DY et al. based on the Multicenter Registry revealed total of 745 SCAR cases (384 SJS/TEN cases and 361 DRESS cases) due to 149 drugs. The main causative drugs suspected were allopurinol (14.0%), carbamazepine (9.5%), vancomycin (4.7%), and anti-tubercular agents (6.3%). Carbonic anhydrase inhibitors (100%), nonsteroidal anti-inflammatory drugs (84%), and acetaminophen (83%) were common offending drugs for SJS/TEN whereas dapsone (100%), antituberculous agents (81%), and glycopeptide antibacterials (78%) were associated with DRESS. The overall mortality rate reported in this study due to SCARs cases was 6.6% (SJS/TEN-8.9% and DRESS-4.2%) [15]. The phase 1 of regiSCAR project by the European community (last updated on October 25, 2014), includes potential 1889 (69.39%) cases of SJS/TEN/GBFDE/EEMM, 364 (13.37%) cases of AGEP, 469 (17.22%) cases of DIHS/DRESS. Of these suspected cases, the definite or probable cases of SJS/TEN- 1232 (65.21%), EEMM- 251 (13.28%), GBFDE- 5 (0.26%), AGEP- 228 (62.63%) and HSS/DRESS- 281 (59.91%) [16].
