UNASSIGNED: Clinically amyopathic dermatomyositis (CADM) is a rare subtype of dermatomyositis that presents with cutaneous features and no muscle involvement. This case report describes a 26-year-old woman with recurrent and multiple digital ulcerations coinciding with the start of winter each year. There was no evidence of myopathy, and antibody testing yielded negative results. A diagnosis of CADM was ultimately made based on clinicopathologic correlation. The patient\'s ulcers demonstrated excellent response to a combination therapy of hydroxychloroquine and potent topical and systemic steroids. Herein, the authors discuss the pathologic and immunologic characteristics of CADM.

UNASSIGNED: Juvenile dermatomyositis (JDM) is a systemic autoimmune disease primarily involving the muscles and skin; it can also affect the central nervous system (CNS). The relevant literature provides limited information regarding the characteristics of JDM with CNS involvement.
UNASSIGNED: We reviewed patients with JDM who were hospitalized at our center between January 2016 and August 2023, with a focus on those with CNS involvement. The aim was to provide detailed case reports on these patients, and to summarize the relevant literature about the characteristics of similar cases.
UNASSIGNED: Among 193 hospitalized patients with JDM, two (1.03%) had CNS involvement. Two patients, a 5.5-year-old girl and an 11-year-old boy, were admitted with severe proximal muscle weakness and seizures, and presented with active cutaneous vasculitis. Both were ultimately diagnosed with JDM, with CNS involvement. Both patients had confirmed presence of anti-NXP2 antibody through myositis-specific antibody analysis. Additionally, they all exhibited hyperferritinemia and thrombocytopenia. Salvage therapies like intravenous methylprednisolone (IVMP) pulse therapy and/or plasma exchange were administered successfully. At final follow-up, both patients had achieved complete clinical response and full neurological recovery. Our literature review identified nine similar case studies. CNS involvement usually occurred within the first 10 months of the disease course, and most of these patients had fatal outcomes, with a mortality rate of 66.6% (6/9). Including the two patients described herein, the median age for disease onset is 10.5 years (range 4-17 years), and the male: female ratio is 6:5. Seizures are the most common neurological symptom, accompanied by active cutaneous vasculitis. The brain biopsies showed two distinct pathological presentations: one was central nervous system vasculitis, and the other was cerebral macrophage activation syndrome.
UNASSIGNED: CNS involvement is a rare but life-threatening JDM complication. Herein, our cases and the literature indicate that it typically occurs within the first 10 months of the disease course and manifests as seizures, often accompanied by active cutaneous vasculitis, with fatal outcomes. Timely implementation of salvage therapies, like IVMP pulse therapy and plasma exchange, may significantly impact patient outcomes.

Dermatomyositis is a rare, autoimmune systemic disorder of unknown aetiology that presents as a constellation of clinical symptoms and signs primarily affecting skin and muscles. Patients with dermatomyositis can present with rare \"non-canonical\" manifestations. Focal or generalised oedema is an infrequent and often overlooked symptom of the disease, while spontaneous intramuscular haemorrhage is an even rarer and under-recognised, life-threatening complication that constitutes a medical emergency for clinical physicians. There are no known predisposing factors able to predict which patients will develop this complication and specific instructions considering treatment approach are currently lacking. Herein, we present a case of a patient with dermatomyositis complicated by both anasarca and spontaneous intramuscular haemorrhage. In order to raise awareness and timely diagnosis of such patients, we provide a review of the relevant literature and of the cases reported this far.

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.

Intravenous immune globulin (IVIG) is a manufactured blood product commonly used to treat immunodeficiency syndromes, inflammatory disorders, and autoimmune diseases of the skin. The use of IVIG in dermatology has evolved and expanded over time, serving as a useful therapeutic intervention for several inflammatory skin disorders. In addition to demonstrating efficacy in treating several cutaneous pathologies, IVIG also mitigates the need for steroids or other immunosuppressant medications in many dermatologic diseases. This review highlights the evidence for IVIG use across several dermatologic conditions, emphasizing the dosing regimens and safety considerations.

Idiopathic inflammatory myopathy (IIM) summarizes rare, systemic autoimmune conditions primarily characterized by inflammatory damage to the skeletal muscle. Although primary damage occurs to the muscle, these IIM-related conditions involve other organs, including the skin, lungs, upper gastrointestinal tract, joints, and heart. While many patients have an adequate response to immunosuppressive treatment, some patients develop rapidly progressive and treatment-resistant life-threatening courses. Treatment-resistant IIM is challenging for the treating physician and requires interdisciplinary and individualized treatment approaches. Extracorporeal therapy is one option for rescue therapy, with immunoadsorption (IA) having proven more effective than plasma exchange regarding the removal of circulating antibodies. Despite its efficacy and desirable safety profile, the clinical value of IA use in IIM is understudied with no controlled trials reported. Here, we present a review of the current knowledge regarding the management of treatment-resistant IIM and the cases of three patients with treatment-resistant IIM (two with dermatomyositis and one with immune-mediated necrotizing myopathy) who have successfully been treated with IA. All patients responded well to the therapy and experienced no IA-related complications. Taken together, we found IA to be a safe and effective treatment option in treatment-resistant IIM.

Systemic autoinflammatory diseases (SAIDs) are distinct from autoimmune diseases. The former primarily results from abnormal innate immune response and genetic testing is crucial for disease diagnosis. Similar cutaneous involvement is a main feature for both SAID and dermatomyositis (DM), so they can be confused with each other. A literature search of PubMed and MEDLINE was conducted for relevant articles. The similarities and differences between these two types of diseases were analyzed. We found phenotypic similarities between these two types of disorders. Accumulating data supports a major role of the innate immune system and a similar cytokine profile. Molecular testing using an autoinflammatory disease gene panel may help identify SAID patients from the DM population and may offer therapeutic benefit using interleukin-1 (IL-1) inhibitors. A subset of DM, notably amyopathic dermatomyositis in the absence of autoantibodies may be on the spectrum of autoinflammatory disease.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM)-associated interstitial lung disease (ILD) can sometimes be complicated by pneumomediastinum, although tension pneumomediastinum is extremely rare. We herein report a case of anti-MDA5 antibody-positive DM-ILD that worsened subcutaneous and mediastinal emphysema during treatment. Hypotension and worsening respiratory failure were observed on day 20 of treatment. Mediastinal drainage under video-assisted thoracoscopic surgery promptly improved the patient\'s circulatory and respiratory status. Tension pneumomediastinum is a rare complication; however, it is a serious condition that may lead to hypotension or cardiac arrest and requires a prompt diagnosis and treatment.

Although the clinical efficacy of tofacitinib has been reported in adult patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive (Ab+) dermatomyositis, data on its use in refractory juvenile dermatomyositis (JDM) are scarce. We describe two female Japanese patients with anti-MDA5 Ab + JDM and rapidly progressive interstitial lung disease who achieved remission by adding tofacitinib to existing immunosuppressive drugs and present a literature review. While both patients received various immunosuppressive or anti-inflammatory treatments for induction therapy, remission could not be achieved. Subsequently, tofacitinib was administered to reduce the Krebs von den Lungen-6 level 5 months after diagnosis in one patient; the other patient received tofacitinib 4 months after diagnosis to reduce ferritin levels and skin manifestations. Subsequently, both patients achieved remission, and prednisolone was withdrawn. Tofacitinib reduced the interferon signature associated with dermatomyositis/JDM disease progression and exerted a therapeutic effect on dermatomyositis/JDM. We found six published cases from five articles of tofacitinib for refractory anti-MDA5 Ab + JDM. Except for one case of herpes simplex meningitis, the other cases, including ours, had improved disease activity without severe adverse events, and steroids and immunosuppressive medicines could be tapered. Tofacitinib could be considered an available therapy for refractory anti-MDA5 Ab + JDM.

Anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis (anti-MDA5-DM) is frequently complicated by progressive interstitial lung disease (ILD), the prognosis of which is poor, and management is a major challenge. We treated three patients with anti-MDA5-DM-associated ILD (anti-MDA5-DM-ILD) using the Janus kinase (JAK) inhibitor, baricitinib, which improved lung opacities and saved two patients. We reviewed 6 patients with anti-MDA5-DM-ILD who had been treated with tofacitinib at our institution. Five of the patients survived, although discontinuation of tofacitinib due to complications was frequently observed. In addition, a literature search of patients with anti-MDA5-DM-ILD who were treated with JAK inhibitors yielded 21 articles involving 79 cases. All patients except one were treated with tofacitinib, and the survival rate was 75.9%. Although not statistically confirmed, the deceased patients tended to be older and had higher ferritin levels. A total of 92 complications were observed, 11 of which resulted in JAK inhibitor discontinuation. Cytomegalovirus reactivation comprised a substantial percentage of all complications and of those patients who required JAK inhibitor discontinuation. Five cases with fatal infective complications were also observed. While tofacitinib has been proposed to be a therapeutic option for anti-MDA5-DM-ILD, other JAK inhibitors, including baricitinib, are a treatment option. Further investigation is warranted to optimize treatment of anti-MDA5-DM-ILD.