A Brief Report on the Clinical Features of Cutaneous Drug Reactions

Dear Editor, We read with great interest the article by Sinha et al.,[1] titled A Clinico-Epidemiological Study of Cutaneous Adverse Drug Reactions in a Tertiary Care Centre of Eastern India, published in the Indian Journal of Dermatology (Jan–Feb 2024). The study provides valuable insights into the clinical patterns and causative agents of cutaneous adverse drug reactions (CADRs) in the Indian population. Given the geographical and ethnic variability in drug reactions, we would like to contribute to this discussion by comparing their findings with data from our observational study on drug eruptions conducted in Turkey. The objective of our study was to analyse the spectrum of drug-induced cutaneous reactions in a Turkish cohort and compare these findings with those reported in the Indian population by highlighting similarities and differences between these two distinct populations. We aim to enhance the understanding of CADR patterns and the potential role of genetic, environmental and prescribing differences in shaping these variations. Our study included 51 patients (54.9% male and 45.1% female), with the highest age distribution observed in the 61–70 age group (25.5%). Conversely, the Indian study involved 72 patients (59.72% male and 40.28% female), with the highest proportion of patients in the 21–30 age group (33.33%). The older age distribution in our cohort may reflect Turkey’s aging population compared to the relatively younger demographic profile in India.[2] The most common CADR pattern in the Turkish study was maculopapular drug eruption (47.1%), followed by urticaria/angioedema (13.7%), whereas in the Indian study, fixed drug eruption was most frequently observed (48.61%), followed by Stevens–Johnson syndrome (SJS)–toxicepidermal necrolysis (TEN) spectrum (16.66%) [Figure 1]. Underlying pharmacogenetic differences may influence these variations. For instance, certain human leukocyte antigen (HLA) alleles associated with severe drug hypersensitivity reactions, such as HLA-B15:02 and HLA-A31:01, show significant differences in prevalence between South Asian and European-derived populations, which may affect individual susceptibility to CADRs.[3] Additionally, a previous Indian study reported a higher prevalence of SJS–TEN than Western countries. This may be related to the widespread use of combination or fixed-dose medications in India, as well as the earlier discontinuation of suspected drugs at the onset of even mild skin reactions in Western clinical practice.[4]Figure 1: Distribution of clinical patterns in cutaneous adverse drug reactions (CADRs). The most common clinical pattern was maculopapular eruption, followed by urticaria. AGEP: Acute Generalized Exanthematous Pustulosis; DRESS: Drug Reaction with Eosinophilia and Systemic Symptoms; SJS/TEN: Stevens–Johnson Syndrome/Toxic Epidermal NecrolysisBeyond genetic predisposition, environmental factors like diet may further modulate drug metabolism. Traditional Indian diets, often rich in spices such as turmeric, black pepper, and ginger, contain bioactive compounds that can induce or inhibit cytochrome P450 enzymes, thus altering drug pharmacokinetics.[5] These effects may influence the development or presentation of CADRs and could partly explain inter-population differences. Regarding causative drugs, both studies found antibacterials to be the leading cause (49% in Turkey vs. 54.16% in India), followed by nonsteroidal anti-inflammatory drugs (13.7% in Turkey vs. 15.27% in India) [Figure 2]. The Naranjo scale assessment showed that 60.8% of cases in the Turkish study were classified as ‘probable’, compared to 80.55% in the Indian study, indicating a higher certainty of drug causality in the latter. Further multi-centre studies incorporating genetic and pharmacovigilance data are needed to explore the underlying causes of these regional differences.Figure 2: Distribution of causative drug categories in cutaneous adverse drug reactions (CADRs). Antibacterial agents were the most common causative drugs, followed by NSAIDs. NSAIDs: Nonsteroidal anti-inflammatory drugsIn conclusion, our comparative analysis highlights notable differences in CADR patterns between Indian and Turkish populations. Understanding these variations may improve early diagnosis and management strategies for drug-induced skin reactions. We commend Sinha et al.[1] for their valuable contribution and encourage continued collaborative research to advance our understanding of CADRs in diverse populations. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.