Investigating the disparities among drug categories in drug-induced dermatomyositis: A systematic review.

Drug-induced dermatomyositis (DIDM) is a rare and underestimated variant of dermatomyositis (DM) characterized by muscle damage and skin rash and related to certain drug exposure. The spectrum of drugs causing DIDM has evolved over time, originally implicating hydroxyurea, penicillamine, and statins as causative agents. Tumor necrosis factor α inhibitors and immune checkpoint inhibitors have also been associated with such conditions. To bridge the gap between current literature and clinical practice, and therefore guide clinicians, we conducted a comprehensive review of English literature from Pubmed, EMBASE, and MEDLINE. Our analysis included demographic data, clinical features, laboratory findings, therapeutic outcomes, and extant research pertaining to the probable pathogenesis of DIDM induced by various drugs. Furthermore, we categorized the drugs involved in DIDM cases into biologics and traditional agents for subsequent statistical analysis. Over time, there has been a gradual accumulation of reported DIDM cases. A total of 69 published DIDM cases were documented in our study, among which 33 should be attributed to biologics and the remaining 36 to traditional drugs. Interestingly, 41 of all DIDM cases had a previous history of malignancies. Additionally, DIDM cases exhibited similar cutaneous and muscular manifestations to classic DM, with the exception of cases induced by hydroxyurea, which did not entail muscle damage. Positive antinuclear antibodies and anti-TIF1-γ autoantibodies have been predominantly observed in biologics-induced cases, while positive anti-TIF1-γ antibodies were merely reported in the cases that were primarily diagnosed with malignant diseases and exposed to ICIs afterwards. Anti-TIF1-γ antibodies may potentially serve as a red flag in the identification of co-existing malignant diseases in DM patients. We also provided a comprehensive summary and exploration of potential mechanisms lying behind drug-induced dermatomyositis. In conclusion, our review consolidates the current literature on DIDM, highlighting the evolving spectrum of medications and elucidating the differences in clinical manifestations, laboratory findings, and underlying mechanisms.