A Clinical Study on Cutaneous Adverse Drug Reactions

Abstract

BACKGROUNDAdverse drug reactions (ADR) are a legacy of the rapid and newer developments made in the field of pharmaceuticals worldwide every day. They represent an important but underestimated cause of morbidity, increased health expenditure, hospital admissions and even mortality.This study focuses on the various morphological patterns of cutaneous ADR, the causative drugs and the outcome of the reactions. It also aims to find out the probable causative drugs using an in vivo test in the form of patch test. MATERIALS AND METHODSThis is a descriptive study undertaken in the Department of Dermatology and Venereology, Medical College Hospital, Thiruvananthapuram, South India for a period of one year, which included 121 clinically diagnosed cases of cutaneous adverse drug reactions. RESULTS92 of them presented with complaints of skin lesions (96.7%); 24 patients had taken penicillins (19.8%) which was the predominant drug; 59 patients (48.8%) had developed reaction within 3 days of administration of the drug. Erythematous macules, papules and small plaques were noticed in 68 patients (56.2%); 43 patients (35.5%) had associated mucosal lesions with majority having involvement of more than one mucosal site. Patch test was done in 39 patients (32.2%) and a positive test result was obtained in 12 cases (9.9%). Exanthematous reactions were observed in 48 patients (39.7%) and urticaria and angioedema in 34 patients (28.1%). There were 18 cases (14.9%) in the SJS-TEN complex. Exanthematous reactions were commonly produced by anticonvulsants in 16 patients (33.33%). CONCLUSIONThis prospective descriptive study on cutaneous adverse drug reactions in 121 cases showed the commonest pattern of drug reaction being exanthematic type followed by urticaria/angioedema and SJS/TEN complex. The commonest offending drug group was NSAIDS, in which paracetamol and diclofenac were the commonest individual drugs imputed followed by anticonvulsants and antibiotics. Penicillins and cephalosporins were the commonest antibiotics responsible. The previously implicated carbamazepine as the commonest cause for severe cutaneous adverse reactions has been taken over by phenytoin as observed in this study. The in vivo patch test using the suspected offending drug as the antigen was positive in 30.7% of the tested cases indicating its role as an adjunct to clinical diagnosis as in a few earlier studies.