Uncovering the Triggers: A Comprehensive Review of Drug-Induced Dermatomyositis

Original Article: Causes and Clinical Presentation of Drug-Induced Dermatomyositis

What are the key takeaways of this article?

Drug-induced dermatomyositis (DM) is an inflammatory myopathy characterized by skin rashes and muscle weakness, and triggered by certain medications. While DM is well-documented, most studies have been limited to case reports or small case series, often from single institutions. There is also limited data on DM induced by immune checkpoint inhibitors, which are increasingly used in cancer therapy. Understanding the diverse causes and clinical presentations of drug-induced DM is thus crucial for improving patient outcomes. This recent systematic review aimed to characterize drug-induced DM's causes and clinical presentations. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, collecting data from PubMed, including original articles, case reports, literature reviews, and observation letters written in English, up to August 22, 2022.

From an initial search of 237 articles, 134 studies met the inclusion criteria and yielded 165 cases of drug-induced DM. Among these patients, 53.3% were female, with a median age of 61 years. The medications most frequently associated with drug-induced DM included hydroxyurea (30.3%), immune checkpoint inhibitors (16.4%), statins (13.3%), penicillamine (6.1%), and tumor necrosis factor inhibitors (6.1%). Clinically, patients presented with symmetrical, photodistributed erythematous scaly plaques, including periorbital erythema and Gottron papules, similar to idiopathic DM. The median time from drug initiation to DM onset was 60 days.

Histopathological analysis confirmed DM in 35.2% of cases, showing vacuolar interface dermatitis and mucin deposition. Common autoantibodies included antinuclear antibody (30.9%) and anti-TIF1-γ (6.7%). Notably, over half of the patients (51.6%) had a history of cancer, particularly chronic myelogenous leukemia and melanoma, highlighting the need for vigilance in cancer patients receiving these medications.

Moreover, muscle weakness was reported in 43.6% of cases, with electromyography and magnetic resonance imaging often confirming myopathy. Additionally, 11.5% of patients underwent chest computed tomography, with 31.6% showing features of interstitial lung disease, emphasizing the multi-system involvement of drug-induced DM and the importance of comprehensive clinical evaluation.

The main concern in managing drug-induced DM is prompt recognition and diagnosis as early identification and appropriate management can significantly minimize therapy interruptions and improve patient outcomes. This study’s findings suggest the need for larger, more detailed studies to develop effective treatments and mitigate the disease burden associated with drug-induced DM.

Overall, this study highlights the necessity for dermatologists to be aware of DM in patients presenting with compatible clinical features and a history of relevant drug exposure. Comprehensive care, including histopathological confirmation and autoantibody testing, is essential for accurate diagnosis and effective management. Finally, this study also provides valuable insights into the causes and clinical presentations of drug-induced DM, underlining the need for further research and longer-term follow-up studies to better understand and manage this condition.

Publication Date: July 9th, 2024

Reference: Caravan S, Lopez CM, Yeh JE. Causes and Clinical Presentation of Drug-Induced Dermatomyositis: A Systematic Review. JAMA Dermatol. 2024;160(2):210–217. doi:10.1001/jamadermatol.2023.5418

Summary By: Megan Lowe