Simvastatin-induced dermatomyositis in a 50-year-old man

Causes and Clinical Presentation of Drug-Induced Dermatomyositis: A Systematic Review

Importance

While several medications are known to induce dermatomyositis (DM), most existing studies are case reports or small case series from a single institution. There is also limited information on DM induced by immune checkpoint inhibitors, which are increasingly used in oncologic therapy.

Objective

To characterize causes and clinical presentation of drug-induced DM based on the current literature.

Evidence Review

A systematic review was performed in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines, from inception to August 22, 2022. Articles meeting preestablished inclusion criteria (written in English and classified as original articles, case reports, literature reviews, and observation letters) were selected and data abstracted. Articles that met the scope of the review were also added from reference lists. When possible, study results were quantitatively combined.

Findings

In 134 studies (114 from the literature search and 20 additional studies pulled from reference lists) describing 165 cases, 88 patients (53.3%) were female, and the median (IQR) age was 61 (49-69) years. Among the cases of drug-induced DM, the most common associated medications were hydroxyurea (50 [30.3%]), immune checkpoint inhibitors (27 [16.4%]), statins (22 [13.3%]), penicillamine (10 [6.1%]), and tumor necrosis factor inhibitors (10 [6.1%]). Histopathologic testing, when undertaken, helped establish the diagnosis. There was a median (IQR) of 60 (21-288) days between drug initiation and drug-induced DM onset. History of cancer was reported in 85 cases (51.6%).

Conclusions and Relevance

In this systematic review, drug-induced DM was associated with multiple types of medications, including chemotherapies and immunotherapies. It is essential that dermatologists promptly recognize and diagnose drug-induced DM so that they can guide management to minimize interruption of therapy when possible.

Environmental triggers of dermatomyositis: a narrative review

Dermatomyositis (DM) is an autoimmune disease that affects the skin, lungs, and muscle. Although the pathogenesis of DM is not completely understood, several environmental triggers have been linked to DM onset or flare. This article specifically examines the effects of herbal supplements, drugs, infections, ultraviolet (UV) radiation, and environmental pollutants on the onset or exacerbation of DM. Herbal supplements such as Spirulina platensis, Aphanizomenon flos-aquae, Chlorella, Echinacea, and Alfalfa have been implicated and are frequently used in health foods. Medications such as hydroxyurea, TNF-α inhibitors, immune checkpoint inhibitors (ICI), and penicillamine, as well as certain viral infections, such as parvovirus B19, coxsackie virus, polyomavirus, Epstein-Barr virus (EBV), hepatitis, influenza, and human immunodeficiency viruses (HIV) have been associated with DM onset. Bacterial infections and vaccinations have also been linked to the development of DM. Additional environmental factors, including UV radiation and air pollutants, such as silica, biological/mineral dust, and particulate air matter from vehicle and industrial emissions, may also play a role in DM pathogenesis. Overall, there is general agreement that an autoimmune attack of the skin, muscle, and lungs in DM can be triggered by various environmental factors and warrants further investigation.

Weak Knees: A Case of Atorvastatin-induced Dermatomyositis

HMG-CoA reductase inhibitors (statins) are one of the most widely used medications in the primary care setting, and like any medications they have many side effects. The common ones include myalgias and rare ones include dermatomyositis. Here we present the case of atorvastatin-induced dermatomyositis with an unfortunate progression. This mandates a low threshold for first contact doctors to screen their patients for new-onset muscle weakness and rash after starting a statin recently, like our patient who had started atorvastatin several months before. This case adds to the previously reported cases and provides further evidence for statins being triggers of immune-mediated disease. The appropriate management of this condition requires a collaborative effort involving clinical judgment, laboratory testing, and imaging.

Aggressive and fatal statin-induced dermatomyositis: a case report

Statins are widely used and are currently the state-of-the-art treatment for primary and secondary prevention of cardiovascular disease. Although statins are generally well tolerated and present an excellent safety profile, adverse effects from muscle toxicity may occur in some patients. Statin-induced dermatomyositis (DM) is a rare adverse event associated with its use and very few fatal cases have been reported. We present the case of a 69-year-old man with early onset DM precipitated by a small dose of simvastatin. Despite immediate cessation of the agent and the use of systemic corticosteroids, the case took a very aggressive and fatal course. Such progression is extremely unusual for statin-induced DM. Despite the safety of statins, we highlight the importance of identifying potential side effects associated with this class of medications. We also emphasize the importance of correct diagnosis and close follow-up of patients with statin side effects.

Polypharmacy and sun exposure: Implications for mitochondrial DNA deletions in skin

Most somatic cells contain many copies of mitochondrial DNA (mtDNA). Because of both the high copy number and the lack of repair mechanisms available to mtDNA, damage to it largely goes unrepaired, and can accumulate over time. Large scale deletions are a recognised type of damage sustained by mtDNA as a consequence of exposure to the ultraviolet light in sunlight. A group of patients were identified as having abnormally high levels of either a 4977 base pair deletion (mtDNA⁴⁹⁷⁷) or 3895 base pair deletion (mtDNA³⁸⁹⁵), in mtDNA from sun exposed skin or skin suspected to be a non-melanoma skin cancer, but not in their non-sun exposed skin biopsies. In three of the four cases, skin cancer was ruled out due to histological testing. Additional factors from these patients' medical histories were studied, and it was noted that they shared diagnoses for multiple pathologies common to an older population, and that they were being treated with the same or related pharmaceuticals, including some that had been known to cause dermal side effects. Investigation into the biochemistry underlying the symptoms, the effects of sun exposure and side effects of the prescribed pharmaceuticals revealed a possible synergistic relationship leading to the localised high levels of mtDNA deletions.

An Unusual Case of Statin-Induced Myopathy: Anti-HMGCoA Necrotizing Autoimmune Myopathy

Statins are some of the most widely prescribed medications, and though generally well tolerated, can lead to a self-limited myopathy in a minority of patients. Recently, these medications have been associated with a necrotizing autoimmune myopathy (NAM). Statin-associated NAM is characterized by irritable myopathy on electromyography (EMG) and muscle necrosis with minimal inflammation on muscle biopsy. The case presented is a 63-year-old woman who has continued elevation of creatine kinase (CK) after discontinuation of statin therapy. She has irritable myopathy on EMG and NAM is confirmed by muscle biopsy. She subsequently tests positive for an experimental anti-3-hydroxy-3-methylglutaryl-coenzyme A (anti-HMGCoA) antibody that is found to be present in patients with statin-associated NAM. Though statin-associated NAM is a relatively rare entity, it is an important consideration for the general internist in patients who continue to have CK elevation and weakness after discontinuation of statin therapy. Continued research is necessary to better define statin-specific and dose-dependent risk, as well as optimal treatment for this condition.

[Statins and autoimmunity]

Statins are the most widely used drugs for both primary and secondary prevention of cardiovascular diseases and those associated with atherosclerosis. About 25 million people are on statin therapy in the world. Although they are well tolerated by most patients and have a safety profile, some patients have muscle level alterations. The biological effects associated with these drugs are known as pleiotropic; they are of such interest and diversity that explains, in part, some of the actions of statins, especially in relation to inflammation and the immune system. Some patients have certain immune disorders that can turn into an undesirable clinical expression. Recent studies have shown that they can trigger autoimmune phenomena. Pathologies have been described in which these agents act as triggers such as immune-mediated necrotizing myopathy or indirectly in dermatomyositis or autoimmune hepatitis, among others. Given the high number of people being treated with statins, we believe that this is a clinically relevant problem and therefore worthy of study.