Amyopathic Dermatomyositis: A Concise Review of Clinical Manifestations and Associated Malignancies

Anti-nuclear matrix protein 2 antibody-positive amyopathic dermatomyositis presenting in a patient with prostate cancer: A case report

Nuclear matrix protein (NXP-2) positive amyopathic dermatomyositis (DM) may present without classic symptoms like muscle weakness, dysphagia, and edema, and mimic conditions like cutaneous lupus. Given DM's association with malignancy and interstitial lung disease, prompt and accurate diagnosis is important. Testing for myositis-specific antibodies aids diagnosis in ambiguous cases.

When a Painful Rash Keeps Recurring: A Case of Seronegative Amyopathic Dermatomyositis Without Neurological Sequelae

We present a case of seronegative amyopathic dermatomyositis (SADM). This clinical entity should be considered in the differential diagnosis of patients with recurring, painful erythematous skin manifestations, and requires close monitoring for the development of neurological manifestations and malignancy. SADM is a rare autoimmune disease that affects the skin and muscles. It is considered a subtype of dermatomyositis (DM), which is a systemic autoimmune disease. The exact cause of SADM is not fully understood but is believed to involve a complex interplay between genetic, environmental, and immunological factors. The diagnosis of SADM is typically made based on clinical evaluation, blood tests, muscle biopsy, and skin biopsy. Treatment options for SADM may include corticosteroids, immunosuppressive drugs, and other supportive measures to manage symptoms and prevent disease progression. A 30-year-old female presented with symptoms of intermittent burning, painful rash primarily on the hands and face. Her medical history was remarkable for a six-year history of multifocal joint pain, chronic low back pain, and intermittent, painful recurring rash in the upper body (face, neck, and chest). Neurological examination revealed scalp tenderness and arthralgia in the upper extremities, with normal motor strength examination. Skin findings included described an erythematous rash on the arms and hands bilaterally. Skin punch biopsy showed compact orthokeratosis, atrophy of the epidermis, interface changes, and increased dermal mucin on the colloidal iron stain, which are suggestive of DM. Electromyography and nerve conduction study were normal. The MRI of the left thigh was normal. C3 and C4 levels were reduced. The extended muscle-specific myositis panel including MDA5 was negative. The patient was placed on a multidrug regimen, including methotrexate, hydroxychloroquine, and prednisone. Within one year of follow-up, she was found to have reductions in skin manifestation and flare-ups. Clinicians should consider amyopathic DM (ADM) in the differential diagnosis of patients with recurring, painful skin manifestations. This condition can be easily overlooked as the development of neurological sequelae may be present much later in the course. We highlight the need for a multi-disciplinary management approach for patients with this unique diagnosis. Close monitoring for the development of neurological manifestations and associated sequelae including malignancy is recommended.

Pitfalls in the Diagnosis and Management of an Unusual Presentation of Clinically Amyopathic Dermatomyositis: A Case Report Written With the Assistance of ChatGPT

Clinically amyopathic dermatomyositis (CADM) is a rare form of dermatomyositis. Patients with this condition present with the typical skin findings of dermatomyositis but lack the characteristic muscle weakness associated with dermatomyositis. This case presentation highlights the unusual clinical manifestation of CADM in a 49-year-old Vietnamese female. The patient initially presented with persistent hyperpigmented plaques on her hands, which did not respond to the standard treatment for atopic dermatitis. The patient later developed respiratory failure and lung fibrosis in Vietnam. This case underscores the challenges in diagnosing and managing CADM, particularly in patients with atypical presentations, and emphasizes the difficulties in managing such cases of CADM in the community setting.

Malignancies in systemic rheumatic diseases: A mini review

There is an increased risk of malignancies in patients with many systemic rheumatic diseases, which negatively impact on their quality of life. The risk and types of malignancies can differ by the type of rheumatic diseases. Possible mechanisms linking them are dynamic and complicated, including chronic inflammation and damage in rheumatic disease, inability to clear oncogenic infections, shared etiology and some anti-rheumatic therapies. Although certain disease-modifying anti-rheumatic drugs (DMARDs) have been proved to be potentially carcinogenic, the majority of them were not associated with increased risk of most malignancies in patients with systemic rheumatic diseases.

Ovoid palatal patch: a portentous sign in dermatomyositis

A 58-year-old woman presented with 1-month history of several erythematous papules and plaques over bilateral knuckle joints (Figure 1a). Physical examination revealed some ill-defined erythematous macules and patches over her forehead, nasolabial fold, V-neck, upper back, and lateral thighs. She also complained of lower limbs weakness in recent two weeks. Notably, there is an asymptomatic, symmetric erythematous patch intermixed with white macules across the midline hard palate (Figure 1b). A skin biopsy was performed on one of the metacarpophalangeal joints of her right hand, which correlated with dermatomyositis (DM). Myositis-specific autoantibodies screen for DM were strongly positive for anti-transcription intermediary factor 1-gamma (anti-TIF1-γ, 176 U/ml). Tumor markers survey revealed elevated carbohydrate antigen (CA) 125 (68 U/ml) and CA 15-3 (31.7 U/ml). Malignancy screening with computer tomography of pelvis disclosed a right ovarian tumor with multiple small nodular opacities in the pelvis, as well as small amount of ascites. She underwent optimal debulking operation for tumor removal and pathology revealed a high-grade ovarian serous carcinoma with omental and peritoneal metastases. The cutaneous and oral mucosal lesions subsided after systemic corticosteroids were prescribed.

Clinical Characteristics and Management of Patients With Clinical Amyopathic Dermatomyositis: A Retrospective Study of 64 Patients at a Tertiary Dermatology Department

Background: Clinical amyopathic dermatomyositis (CADM) represents a subtype of 5–20% of patients with dermatomyositis (DM), which can be categorized into amyopathic dermatomyositis (ADM) and hypomyopathic dermatomyositis (HDM). The characteristics of patients with CADM are still limited in English literature.

Objective: To investigate clinical features, cutaneous findings, diagnostic accuracy, and treatment regimen of CADM patients.

Methods: Sixty-four patients diagnosed with CADM at Peking Union Medical College Hospital by dermatologists were retrospectively analyzed. Data were recorded in the electronic database at each offline clinical consultation and directly extracted from medical records. 2017 EULAR/ACR criteria for idiopathic inflammatory myositis (IIM) classification was used to identify and classify patients with CADM. Published studies were searched to extract relevant data of CADM patients.

Results: This cohort included 38 ADM patients and 26 HDM patients. 2017 EULAR/ACR criteria classified 67.2% of patients with CADM into probable or definite DM. Antimalarials were given to a majority of CADM patients (72.6%, n = 45). However, 68.8% (31 out of 45) required at least one aggressive agent combined with hydroxychloroquine due to insufficient response or side effects. The median of systemic treatments in HDM was significantly higher than ADM (p = 0.007). The number of ADM patients using antimalarials as monotherapy was significantly higher than that of HDM patients (p = 0.031), while the number of HDM patients receiving steroids combined with immunosuppressants was significantly higher (p = 0.025). The median of Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) score improvement was 11.5 and 10.5 for ADM and HDM after a median follow-up of 31.5 and 32.5 months, respectively. Six patients with normal muscle strength developed muscle weakness after a median of 10.5 months (IQR 9-13), and elevated inflammatory markers at initial visit might indicate their muscle weakness development.

Conclusions: 32.8% of patients may be overlooked using the three skin variables of 2017 EULAR/ACR criteria. The response rate to single hydroxychloroquine in our cohort was 68.8%. Detailed treatment modalities were different among ADM and HDM. Long-term monitoring for the development of myositis in patients with CADM, especially those with elevated inflammatory markers at initial visit, may be warranted.

Amyopathic dermatomyositis combined with peripheral neuropathy

We provide the first report of amyopathic dermatomyositis combined with peripheral neuropathy. Our patient, a 49-year-old woman, initially experienced muscle weakness and tingling sensations in her legs, and nerve conduction study findings and the detection of antiganglioside antibodies indicated that she had autoimmune peripheral neuropathy. The unexpected presence of skin lesions, interstitial pneumonia and antibodies to melanoma differentiation-associated protein 5 prompted an additional diagnosis of amyopathic dermatomyositis. No previous report has described amyopathic dermatomyositis with peripheral neuropathy, and the present case provides evidence for the once-controversial concept of neuromyositis.

Inflammatory breast cancer associated with amyopathic dermatomyositis: a case report

Background

Dermatomyositis is associated with malignant tumors including breast cancer, and inflammatory breast cancer is considered to have a poorer prognosis than most breast cancers.

Case presentation

A 74-year-old Asian woman, developed erythema on her face, back, and the back of her hands, 3 weeks before attending our department. At the same time, she had noticed a right breast mass and redness of the skin of the breast. The clinical findings and vacuum aspiration biopsy diagnosed inflammatory breast cancer and neoadjuvant chemotherapy was performed. The mass and enlarged axillary lymph nodes had shrunk, therefore a total mastectomy was performed. The sentinel lymph node biopsy was negative. She was discharged 7 days after surgery without any complications. She has received a postoperative aromatase inhibitor and is alive without recurrence. The dermatomyositis also began to improve with the start of her chemotherapy and has not recurred since the surgery.

Conclusions

Neoadjuvant chemotherapy was performed for inflammatory breast cancer with dermatomyositis, and tumor shrinkage was confirmed. A total mastectomy without axillary lymph node dissection was performed. Dermatomyositis and breast cancer have not recurred. Dermatomyositis may have been a paraneoplastic syndrome due to breast cancer.

Malignancy in dermatomyositis: A retrospective study of 201 patients seen at the University of Pennsylvania

BACKGROUND

There is an increased incidence of malignancy in patients with dermatomyositis. It is unknown if the risk differs between the subtypes of dermatomyositis.

OBJECTIVE

To (1) compare the prevalence of malignancy-associated dermatomyositis between patients with classic and clinically amyopathic disease and (2) determine factors associated with an increased risk of malignancy-associated disease.

METHODS

Retrospective cohort study of 201 patients with adult-onset dermatomyositis prospectively enrolled in a longitudinal dermatomyositis database between July 2008 and April 2018 at an outpatient dermatology urban tertiary referral center. The main outcome measure was a diagnosis of malignancy, excluding nonmelanoma skin cancer.

RESULTS

There were 201 patients with adult-onset dermatomyositis: 142 (71%) classic and 59 (29%) clinically amyopathic. Within 2 years of diagnosis, the prevalences of malignancy-associated classic and clinically amyopathic dermatomyositis were 9.9% and 1.7%, respectively. In this time period, patients who were older at dermatomyositis diagnosis (P = .01) and had the classic subtype (P = .04) were significantly more likely to have an underlying malignancy on multivariable regression analysis.

LIMITATIONS

This was a retrospective study of prospectively collected data at a single tertiary referral center.

CONCLUSION

Older age and classic dermatomyositis are independent risk factors for malignancy-associated dermatomyositis within 2 years of disease onset.

Ovoid palatal patch: a clue to anti-TIF1γ dermatomyositis

An 80-year-old woman presented with a several-year history of progressive hair loss and scalp pruritus. No other rashes or muscle weakness were noted on examination. Scalp biopsy showed interface dermatitis, dense perivascular and periadnexal lymphocytic infiltrate, mucin and scarring alopecia. Laboratory analysis did not show evidence of myositis. The patient was started on hydroxychloroquine for possible cutaneous lupus erythematosus. On follow-up, she presented with a new violaceous rash on the superior eyelids and a well-defined oval patch on the mid-hard palate suspicious for dermatomyositis. Myositis-specific autoantibodies revealed presence of anti-transcriptional intermediary factor-1γ (anti-TIF1γ) in the serum. Anti-TIF1γ autoantibody-positive dermatomyositis is a newly recognised subtype of dermatomyositis that is highly associated with amyopathic disease and has an increased risk of malignancy, making prompt diagnosis crucial. This case highlights the utility of a thorough oral exam in patients suspected to have connective tissue disease as the distinctive ovoid palatal patch is nearly pathognomonic for anti-TIF1γ dermatomyositis.

Value of 18F-FDG PET/CT in the detection of occult malignancy in patients with dermatomyositis

Aim

Dermatomyositis (DM) is an inflammatory myopathy in adults that is strongly associated with malignancy. The aim of this study was to evaluate whether whole-body ¹⁸F-FDG PET/CT imaging can offer a standard option searching for underlying malignancy in DM patients.

Methods

Seventy-five patients diagnosed with DM were referred to our department for whole-body ¹⁸F-FDG PET/CT to determine whether the patients suffered from malignant tumor. All PET images were analyzed by two experienced nuclear medicine physicians separately.

Results

According to the ¹⁸F-FDG PET/CT results, 19 patients were suspected to suffer from malignant tumor, then biopsy was performed. Of the 19 patients, 17 patients were confirmed to have malignant tumor. The pathological types were: nasopharyngeal carcinoma, rectal cancer, lung cancer, colon cancer, gastric cancer, gallbladder cancer, kidney cancer, ovarian cancer, breast cancer, lymphoma and vertebral metastatic adenocarcinoma of unknown origin. No malignancy was found for the 56 PET-negative patients during follow-up. For the age between 17 patients with malignancy and 58 patients without malignancy, no significant difference was observed.

Conclusion

¹⁸F-FDG PET/CT may be a sensitive and effective method in determining whether the patients with DM suffered from malignant tumor.

Noninvasive positive pressure ventilator deteriorates the outcome of pneumomediastinum in anti-MDA5 antibody-positive clinically amyopathic dermatomyositis

BACKGROUND

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab)-positive clinically amyopathic dermatomyositis (CADM) with pneumomediastinum (PNM) is a life-threatening condition. We aim to determine the prognostic factors affecting survival of patients with anti-MDA5 Ab-positive CADM complicated with PNM.

METHODS

We retrospectively established a cohort of patients with anti-MDA5 Ab-positive CADM complicated with PNM from April 2013 to July 2019. Demographic data and clinical characteristics from medical records were analyzed and variables were compared between survivors and nonsurvivors. We performed univariate and multivariate survival analyses by Cox regression. Survival curves were depicted by the Kaplan-Meier method.

RESULTS

Among 133 patients with anti-MDA5 Ab-positive CADM, 20 were diagnosed with PNM. The cumulative estimated Kaplan-Meier survival rate was 85% at 1 week, 55% at 1 month, and 40% at 1 year. Univariate analysis indicated several factors associated with survival. Worse liver function (AST, p = 0.043; LDH, p = 0.002; TBIL, p = 0.038), higher CRP level (p = 0.044), higher HRCT score (p = 0.022), and using noninvasive positive pressure ventilation (NPPV) (p < 0.01) were associated with poor prognosis. In a multivariate Cox regression model, AST level and using NPPV were indicated to be independent predictors of poor prognosis.

CONCLUSION

In this research, we found that the incidence rate of PNM in anti-MDA5 Ab-positive CADM was 15.5%, obviously higher than in classical DM. The application of noninvasive positive pressure ventilator (NPPV) and higher AST level were independent risk factors for survival.Key Points• Anti-MDA5 Ab-positive CADM complicated with PNM is a life-threatening condition with an incidence rate of 15.5%.• The application of NPPV and worse liver function were independent risk factors for survival of anti-MDA5 Ab-positive CADM patients complicated with PNM.

Anti-TIF1gamma Antibody-Positive Dermatomyositis Associated with Myelodysplastic Syndrome: Response to Treatment

Dermatomyositis (DM) classically presents as a dyad of typical cutaneous findings and varying degrees of proximal muscle weakness. Interestingly, the development of DM may signal underlying malignancy, and numerous myositis-specific autoantibodies have been associated with this paraneoplastic phenomenon. Positivity for anti-TIF1gamma antibody, in particular, raises suspicion for cancer-associated DM. Here, we present an unusual case of anti-TIF1gamma antibody-positive DM that ultimately lead to the diagnosis of myelodysplastic syndrome (MDS). Importantly, topical treatment and chemotherapy targeting MDS resulted in a swift and remarkable amelioration of cutaneous disease.

Angioedema Masqueraders

Angioedema is a common reason for referral to immunology and allergy specialists. Not all cases are in fact angioedema. There are many conditions that may mimic its appearance, resulting in misdiagnosis. This may happen when a clinician is unfamiliar with conditions resembling angioedema or when there is a low index of clinical suspicion. In this article, we explore a list of differential diagnoses based on body parts, including the lips, the limbs, periorbital tissues, the face, epiglottis and uvula, as well as the genitalia, that may pose as a masquerader even to an experienced eye.

Juvenile Idiopathic Inflammatory Myopathies

The juvenile idiopathic inflammatory myopathies (JIIM) are a group of rare, chronic, autoimmune illnesses that affect muscle and, to a lesser extent, skin. The presence of new-onset weakness and, in juvenile dermatomyositis, typical rahes, should lead to consideration of these diagnoses. Careful evaluation to exclude alternative diagnoses is needed. Investigations include a variety of blood tests, imaging, and possibly muscle biopsy. Validated clinical assessments are available for monitoring. Standard treatment includes corticosteroids and methotrexate and often extends beyond 1 year. Outcomes are generally good, but disease persistence remains problematic. Early involvement of providers with expertise in JIIM is essential.

Clinically amyopathic dermatomyositis associated with anti-MDA5 antibody

Clinically amyopathic dermatomyositis (CADM) is a rare entity that presents with cutaneous manifestations of classic dermatomyositis but without muscle weakness or abnormal muscle enzymes. It is more common in young white and Asian females. A subset of patients with CADM has a specific antibody known as anti-MDA5. These patients have a more aggressive course with distinct cutaneous features, pulmonary involvement and early death. Here, we present the case of a 64-year-old Caucasian male with no significant medical history who was admitted with marked weight loss and a painful rash for 6 months. Patient had no muscle weakness and his rash was characteristic of classic dermatomyositis. Skin biopsy was suggestive of dermatomyositis but muscle enzymes were normal. His serum was positive for anti-MDA5 antibody. Extensive workup failed to detect any malignancy but he did show non-specific interstitial pneumonia. He was treated with prednisone and mycophenolate with good clinical response.

Idiopathic inflammatory myopathies - a guide to subtypes, diagnostic approach and treatment

The idiopathic inflammatory myopathies are a group of conditions characterised by inflammation of muscles (myositis) and other body systems. The diagnosis can be challenging because of the many potential clinical features and extra-muscular manifestations, which may be seemingly unrelated. An accurate diagnosis requires up-to-date understanding of the clinical manifestations, different clinical subtypes and appropriate interpretation of investigations, including newly described serological subtypes.This review will detail the approach to the diagnosis of an idiopathic inflammatory myopathy, based on up-to-date knowledge. The recently updated classification criteria and treatment options will also be described.

Diagnosis and Management of Immune-Mediated Myopathies

Immune-mediated myopathies (IMMs) are a heterogeneous group of acquired muscle disorders characterized by muscle weakness, elevated creatine kinase levels, and myopathic electromyographic findings. Most IMMs feature the presence of inflammatory infiltrates in muscle. However, the inflammatory exudate may be absent. Indeed, necrotizing autoimmune myopathy (NAM), also called immune-mediated necrotizing myopathy, is characterized by a necrotizing pathologic process with no or minimal inflammation in muscle. The recent discovery of antibodies associated with specific subtypes of autoimmune myopathies has played a major role in characterizing these diseases. Although diagnostic criteria and classification of IMMs currently are under revision, on the basis of the clinical and muscle histopathologic findings, IMMs can be differentiated as NAM, inclusion body myositis (IBM), dermatomyositis, polymyositis, and nonspecific myositis. Because of recent developments in the field of NAM and IBM and the controversies around polymyositis, this review will focus on NAM, IBM, and dermatomyositis.