Clinical pattern and causative agents in cutaneous adverse drug reactions: an evidence based approach

Aim: Cutaneous adverse drug reactions (CADRs) are the commonest presentations of drug induced reactions. The present study was conducted to study the clinical pattern, causative agents and magnitude of CADRs. Materials and Methods: A prospective hospital based study was carried out by the department of pharmacology and dermatology in SMHS hospital. The study was conducted from june 2013 to june 2016 on admitted patients of CADRs. After obtaining an informed consent, these reactions were reported on a structured questionnaire based on ADR monitoring form provided by the Central Drug Standard control Organization (CDSCO) Ministry of Health and Family Welfare, Government of India. The CADRs were analyzed for their pattern, causative agents, severity and prognosis. Causality assessment was done by using a validated ADR probability scale of Naranjo as well as WHO-Uppsala Monitoring Centre (WHO-UMC) system for standardized case causality assessment. The management protocols were analyzed for their clinical outcome through a proper follow up period. Results: A total of 65 inpatients were identified as CADRs, 26% were males and 74% were females. Age group ranged from 2 – 65 years with average age of 37 years. 7 different types of CADRs were noted, most common being maculopapular drug eruption (25%), urticarias (18%), SJS(17%), TEN(14%), FDE (14%), anticonvulsant hypersensitivity syndrome(9%) and urticarial vasculitis (3%). TEN was seen in all females (100%) and in no male. Drugs implicated in causing these cutaneous reactions were identified as Phenytoin (24.6%), Fluoroquinolones (20%), Carbamazepine (15.3%), piroxicam i.m(15.3%), lamotrigine (9.2%), phenobarbitone(3%), sulfasalazine (3%), risedronate, cefixime, cefpodoxime, amoxcicillin, ayurvedic medicine and capecitabine all (1.5%). Despite higher reported mortality rates in SJS and TEN all patients survived with 2 patients surviving TEN suffered from long term ophthalmological sequelae of the disease. Conclusion: Present study concludes that CADRs are common manifestations of various drug therapies ranging from simple nuisance rashes to rare life threatening diseases like SJS and TEN. North Indian ethnic population has great predisposition of CADRs due to aromatic antiepileptic drugs, fluroquinolones, oxicam NSAIDs, lamotrigine and other antibiotics. To ensure safe use of pharmaceutical agents and newer molecules/ biologicals post marketing voluntary reporting of severe, rare and unusual reactions remains inevitable.