A Case Series of Different Cutaneous Adverse Drug Reactions Attending the Dermatology Clinic of a Tertiary Care Center

Background: Cutaneous adverse drug reactions (CADRs) constitute a heterogeneous array of immunologically and non-immunologically mediated dermatologic sequelae secondary to pharmacologic exposure.These entities encompass Type I (IgE-mediated anaphylaxis), Type II (antibody-dependent cytotoxicity), Type III (immune complex-mediated vasculopathies), and Type IV (T-cell-mediated delayed hypersensitivity reactions), along with atypical presentations such as pseudoallergic phenomena, idiosyncrasies, and pharmacogenetically predisposed intolerances.Despite accounting for only 2-3% of all adverse drug events, CADRs are disproportionately burdensome due to their diagnostic ambiguity, protean manifestations, and potential for rapid progression to high-mortality syndromes such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).Objective: To delineate the clinical heterogeneity, etiopathogenetic mechanisms, and diagnostic nuances of CADRs through a descriptive analysis of ten paradigmatic cases presenting to a tertiary dermatologic facility.Methods: A prospective observational analysis was undertaken on ten patients manifesting distinct phenotypic variants of CADRs.Comprehensive pharmacological histories, temporal association analyses, histopathological evaluations, and causality assessments (via algorithms such as Naranjo and WHO-UMC) were employed to determine the imputability of suspect agents and characterize the underlying immunopathogenesis. Results:The cohort demonstrated a predominance of male patients under the age of 50.Fixed drug eruptions (FDE) constituted the most prevalent presentation, while severe cutaneous adverse reactions (SCARs)-notably TEN and AGEP-were documented in three individuals.Implicated pharmacologic classes predominantly included beta-lactam antibiotics, cephalosporins, nonsteroidal anti-inflammatory drugs (NSAIDs), and tyrosine kinase inhibitors.Latency periods ranged from immediate-onset urticaria to delayed-onset mucocutaneous erosions.Histopathological correlates included interface dermatitis, subepidermal bullae with necrotic keratinocytes, and spongiotic pustules.Management entailed immediate withdrawal of the culprit drug, supportive care, and, in select SCAR cases, systemic immunomodulation.Conclusions: Cutaneous adverse drug reactions encompass a broad and often diagnostically elusive spectrum of dermatologic pathologies with significant implications for morbidity and mortality.Prompt recognition, mechanistic insight into the immunopathology, and multidisciplinary intervention are paramount, particularly in cases of SCARs.This series underscores the necessity for heightened clinical vigilance, integration of dermato pathology, and application of pharmacovigilance algorithms to enhance diagnostic accuracy and therapeutic outcomes in drug-induced dermatoses.