Cutaneous Tuberculosis: A Comprehensive Review of Etiopathogenesis, Clinical Subtypes, Diagnostic Modalities, and Contemporary Therapeutic Approaches

Background: Cutaneous tuberculosis (CTB) is a rare extrapulmonary manifestation of Mycobacterium tuberculosis infection, with heterogeneous clinical presentations influenced by host immunity, bacterial virulence, and route of inoculation. Despite its declining global incidence, CTB remains a diagnostic and therapeutic challenge due to its paucibacillary nature and histopathological overlap with other granulomatous dermatoses. Objectives: This review elucidates the etiopathogenesis, spectrum of clinical variants (e.g., lupus vulgaris, scrofuloderma, tuberculous gumma), and evidence-based strategies for diagnosis (histopathology, PCR, interferon-gamma release assays) and treatment (multidrug antitubercular therapy, adjunctive surgical interventions). Methods: A systematic literature analysis was conducted using PubMed, Embase, and Cochrane databases (2000–2023), prioritizing clinical studies, case series, and consensus guidelines. Results: CTB accounts for 1–2% of extrapulmonary TB cases, with lupus vulgaris being the most common subtype. Molecular diagnostics (e.g., GeneXpert MTB/RIF) have improved sensitivity over traditional Ziehl-Neelsen staining. Treatment requires standard ATT regimens (e.g., 2HRZE/4HR), though drug-resistant cases necessitate tailored regimens. Conclusion: Heightened clinical suspicion, aided by advanced diagnostics, is critical for timely CTB management. Interdisciplinary collaboration between dermatologists, microbiologists, and infectious disease specialists is paramount to mitigate morbidity.