Clinically amyopathic dermatomyositis: clinical features, response to medications and malignancy-associated risk factors in a specific tertiary-care-centre cohort

Clinical characteristics and symptom progression of dermatomyositis subtypes: A retrospective analysis of a prospective database

BACKGROUND

Disease characteristics of classic dermatomyositis (DM) and clinically amyopathic DM (CADM) are well established, but there exists limited knowledge on the disease progression of these subtypes.

OBJECTIVE

The objective of this study was to longitudinally track and characterize classic DM and CADM patients who experience changes in disease presentation.

METHODS

We conducted a retrospective review of prospectively collected data on 269 DM patients from a longitudinal database.

RESULTS

A total of 51% of the patients had classic DM and 49% had CADM. Forty percent of the classic DM patients became postmyopathic (PmDM). Median Cutaneous Dermatomyositis Disease Area and Severity Index activity (CDASI-A) score was lower in PmDM patients than in classic DM patients (13.0 vs 16.0), but 45% of the PmDM patients had CDASI-A scores > 14. Five percent of the CADM patients developed muscle involvement. Compared with CADM patients, those who developed muscle symptoms had milder skin disease before subtype conversion (median CDASI-A 12.0 vs 16.0) and at subtype conversion (median CDASI-A 9.0 vs 16.0).

LIMITATIONS

This was a retrospective study conducted at a single tertiary-care dermatology clinic.

CONCLUSIONS

Forty percent of the classic DM patients became PmDM. The majority continue with muscle disease, and many continue to have moderate/severe skin disease. CADM has a low risk of progressing to muscle disease, with the extent of skin disease as a potential predictive factor.

IgM nephropathy in a patient with dermatomyositis following COVID-19 vaccination: A case report

BACKGROUND

Dermatomyositis (DM) is a systemic autoimmune disease characterized by distinct skin lesions and a clinically heterogeneous constellation of systemic manifestations. This disease poses a challenge to clinicians because of its rarity, diverse clinical presentations, and variable organ involvement, resulting from an autoimmune attack on affected organs, which could be triggered by environmental factors in genetically susceptible individuals. Renal involvement is rare, with immunoglobulin M (IgM) nephropathy yet to be reported in patients with DM.

CASE PRESENTATION

A 38-year-old man was admitted to Shariati Hospital, affiliated with Tehran University of Medical Sciences, with proximal weakness of the upper and lower extremities that had developed in the preceding month after receiving the Sinopharm COVID-19 vaccine. The patient was diagnosed with DM based on the heliotrope rash, Gottron's papules, progressive proximal muscle weakness, and paraclinical findings. IgM nephropathy developed subsequently, diagnosed by light and immunofluorescence microscopy.

CONCLUSION

We describe the first case of IgM nephropathy in a DM patient following COVID-19 vaccination. This phenomenon requires further investigation into the possible crosslinks between the pathogenesis of IgM nephropathy with DM and the COVID-19 vaccine. Diagnosing renal complications in DM patients promptly and accurately can help to achieve the best outcomes.

Comparison of characteristics and anti-MDA5 antibody distribution and effect between clinically amyopathic dermatomyositis and classic dermatomyositis: a retrospective case-control study

Background

Clinically amyopathic dermatomyositis (CADM) is a distinct subtype of dermatomyositis (DM) characterized by typical DM cutaneous findings but with minimal or no evidence of myositis. It possesses unique features different from classic DM (CDM). Anti-melanoma differentiation-associated gene 5 (MDA5) antibodies were found in CADM and are thought to increase the risk of rapidly progressive interstitial lung disease (RP-ILD) and are present in both CADM and CDM patients, affecting their condition and prognosis. Nevertheless, no large-sample studies have compared all aspects concerning patients with CADM and those with CDM. This study aimed to investigate differences in clinical characteristics and risk factors for mortality between CADM and CDM and to clarify the distribution and impact of anti-MDA5 antibodies in patients with these conditions.

Methods

A retrospective case-control study included 330 patients and collected and analyzed their clinical data from The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Hospital of Traditional Chinese Medicine between January 2015 and July 2022; all patients were followed up to evaluate changes in their condition and prognosis. Several new cohorts were designed around anti-MDA5 antibodies to explore their distribution and impact in CADM and CDM.

Results

We found CADM to be associated with higher rates of mortality, 1-year mortality, interstitial lung disease (ILD), and RP-ILD than CDM. In CADM, RP-ILD, anti-MDA5 antibodies, and high ferritin and lactate dehydrogenase (LDH) levels were identified as independent risk factors for death. In CDM, the neutrophil-to-lymphocyte ratio, anti-MDA5 antibodies, and high ferritin levels were shown to be independent risk factors for death, whereas mechanic's hand was considered a protective factor against it. Anti-MDA5 antibody-positive patients did not exhibit any significant difference based on whether they belonged to the CADM or CDM groups. When no anti-MDA5 antibody-positive patients participated, the ferritin levels and rates of RP-ILD and ILD were still higher in CADM than in CDM; however, such differences decreased, whereas the LDH levels, rates of mortality, and 1-year mortality did not differ. Anti-MDA5 antibody-positive patients consistently showed higher LDH and ferritin levels, lower lymphocyte levels, higher probability of RP-ILD and ILD, and worse prognosis than anti-MDA5 antibody-negative patients, irrespective of whether the patients had DM, CADM, or CDM.

Conclusion

Patients with CADM exhibit relatively worse symptoms, serological findings, and prognosis than those with CDM. Furthermore, patients with CADM and those with CDM have commonalities and differences in risk factors for death. Moreover, CADM may necessitate earlier and more aggressive treatment strategies than CDM. Anti-MDA5 antibodies occur at a high level in patients with CADM, not only affecting the symptoms and prognosis of DM but also having a non-negligible impact on the differences between CADM and CDM. Hence, screening for anti-MDA5 antibodies in patients with CADM and CDM is extremely essential.

The associations between myositis autoantibodies and clinical presentations in dermatomyositis

BACKGROUND

The myositis autoantibodies have been widely used clinically in recent years for the identification of an autoantibody-associated clinical phenotype in dermatomyositis (DM) patients. However, correlations between myositis autoantibodies and clinical presentations in different populations are lacking, especially in Taiwan.

OBJECTIVES

To investigate the correlations among cutaneous manifestations, myositis autoantibodies, and systemic diseases, including interstitial lung disease (ILD) and internal malignancy.

METHODS

A retrospective study of patients with histopathologically confirmed cutaneous manifestations of DM was conducted during 2005 to 2020 in Taiwan. A commercial line blot immunoassay technique was used to detect myositis autoantibodies.

RESULTS

A total of 88 DM patients were enrolled, with a mean age of onset of 49.4 years old. The most common systemic features were myositis (56.8%, 50/88), internal malignancy (22.7%, 20/88), dysphagia (19.3%, 17/88), and ILD (17%, 15/88). Among the enrolled patients, 32 patients received serum myositis autoantibodies examination. The most common autoantibodies were ANA (50.7%, 37/73), followed by anti-TIF1-γ (34.4%, 11/32) and anti-MDA5 (31.3%, 10/32) antibodies. Patients with Gottron sign (OR 5.6), arthritis (OR 23.35), or the presence of anti-MDA5 antibody (OR 11.14) were more susceptible to progressing to ILD, whereas patients with pruritus (OR 1.04), dysphagia (OR 6.73), and the presence of ANA (OR 6.29) had significantly higher risks of developing internal malignancies.

CONCLUSIONS

Physicians should pay special attention to certain clinical features, which can help with the early detection of systemic diseases. Cancer screening and myositis autoantibodies examination should be conducted in all DM patients if applicable.

Identification of Latent Diagnostic Biomarkers and Biological Pathways in Dermatomyositis Based on WGCNA

Introduction

Dermatomyositis (DM) is a chronic autoimmune disease of predominantly lymphocytic infiltration mainly involving the transverse muscle. Its pathogenesis is remaining unknown. This research is designed to probe the latent pathogenesis of dermatomyositis, identify potential biomarkers, and reveal the pathogenesis of dermatomyositis through information biology analysis of gene chips.

Methods

In this study, we utilised the GSE14287 and GSE11971 datasets rooted in the Gene Expression Omnibus (GEO) databank, which included a total of 62 DM samples and 9 normal samples. The datasets were combined, and the differentially expressed gene sets were subjected to weighted gene coexpression network analysis, and the hub gene was screened using a protein interaction network from genes in modules highly correlated with dermatomyositis progression.

Results

A total of 3 key genes-myxovirus resistance-2 (MX2), oligoadenylate synthetase 1 (OAS1), and oligoadenylate synthetase 2 (OAS2)-were identified in combination with cell line samples, and the expressions of the 3 genes were verified separately. The results showed that MX2, OAS1, and OAS2 were highly expressed in LPS-treated cell lines compared to normal cell lines. The results of pathway enrichment analysis of the genes indicated that all 3 genes were enriched in the cytosolic DNA signalling and cytokine and cytokine receptor interaction signalling pathways; the results of functional enrichment analysis showed that all 3 were enriched in interferon-α response and interferon-γ response functions.

Conclusions

This is important for the study of the pathogenesis and objective treatment of dermatomyositis and provides important reference information for the targeted therapy of dermatomyositis.

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.

A Clinical Risk Model to Predict Rapidly Progressive Interstitial Lung Disease Incidence in Dermatomyositis

Background: Rapidly progressive interstitial lung disease (RP-ILD) is a fatal complication of dermatomyositis (DM) and clinically amyopathic DM (CADM). The objective of this study was to evaluate risk markers associated with RP-ILD incidence in patients with DM/CADM and to develop a RP-ILD risk prediction (RRP) model.

Methods: The clinical records of 229 patients with DM/CADM from Peking University People's Hospital, and 97 patients from four other independent clinical centers were retrospectively reviewed. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors associated with later RP-ILD incidence to build a risk score model. The concordance index (C-index) and calibration curve were calculated to evaluate the predictive accuracy of the RRP model.

Results: A multiparametric RRP model was established based on weighted clinical features, including fever (yes, 5; no, 0), periungual erythema (yes, 6; no, 0), elevated CRP (yes, 5; no, 0), anti-MDA5 antibody (positive, 8; negative, 0), and anti-Ro-52 antibody (positive, 6; negative, 0). Patients were divided into three risk groups according to the RRP total score: low, 0–9; medium, 10–19; high, 20–30. The C-index and calibration curve of the RRP model showed a promising predictive accuracy on the incidence of RP-ILD.

Conclusion: The RRP model might promisingly predict the incidence of RP-ILD in DM/CADM patients to guide early individual treatment and further improve the prognosis of DM/CADM patients.

A systematic review and meta-analysis to inform cancer screening guidelines in idiopathic inflammatory myopathies

Objectives

To identify clinical factors associated with cancer risk in the idiopathic inflammatory myopathies (IIMs) and to systematically review the existing evidence related to cancer screening.

Methods

A systematic literature search was carried out on Medline, Embase and Scopus. Cancer risk within the IIM population (i.e. not compared with the general population) was expressed as risk ratios (RR) for binary variables and weighted mean differences (WMD) for continuous variables. Evidence relating to cancer screening practices in the IIMs were synthesized via narrative review.

Results

Sixty-nine studies were included in the meta-analysis. DM subtype (RR 2.21), older age (WMD 11.19), male sex (RR 1.53), dysphagia (RR 2.09), cutaneous ulceration (RR 2.73) and anti-transcriptional intermediary factor-1 gamma positivity (RR 4.66) were identified as being associated with significantly increased risk of cancer. PM (RR 0.49) and clinically amyopathic DM (RR 0.44) subtypes, Raynaud’s phenomenon (RR 0.61), interstitial lung disease (RR 0.49), very high serum creatine kinase (WMD −1189.96) or lactate dehydrogenase (WMD −336.52) levels, and anti-Jo1 (RR 0.45) or anti-EJ (RR 0.17) positivity were identified as being associated with significantly reduced risk of cancer. Nine studies relating to IIM-specific cancer screening were included. CT scanning of the thorax, abdomen and pelvis appeared to be effective in identifying underlying asymptomatic cancers.

Conclusion

Cancer risk factors should be evaluated in patients with IIM for risk stratification. Screening evidence is limited but CT scanning could be useful. Prospective studies and consensus guidelines are needed to establish cancer screening strategies in IIM patients.

Elevated carcinoembryonic antigen predicts rapidly progressive interstitial lung disease in clinically amyopathic dermatomyositis

OBJECTIVES

The present study aimed to determine the correlation between serum carcinoembryonic antigen (CEA) level and the severity of interstitial lung disease (ILD) in clinically amyopathic DM (CADM) patients.

METHODS

We performed a retrospective study including 41 Chinese CADM patients without malignancy. Serum CEA levels, clinical and laboratory findings were collected. Association tests between CEA levels and disease activity parameters were performed.

RESULTS

Among the 41 patients, 16 (39.0%) developed rapidly progressive (RP)-ILD; of them, 14 (87.5%) had elevated serum CEA levels. Multivariate logistic regression analysis indicated that an elevated serum CEA level was an independent risk factor for RP-ILD. The incidence of elevated CEA level was significantly higher in patients with RP-ILD than in those without RP-ILD (87.5 vs 16.0%, P < 0.001). Furthermore, CEA levels were higher in patients with CADM with RP-ILD [26.87 (6.71) μg/l] than in those without RP-ILD [3.23 (0.64) μg/l] (P < 0.001). CEA levels in CADM patients were associated with the ferritin, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase levels, and CT scores of the lungs. Also, elevated CEA levels are related to the organizing pneumonia pattern and lower lung zone consolidation in high-resolution CT. Moreover, the cumulative survival rate was significantly lower (68.4 vs 31.6%, P < 0.001) in the group with a CEA level >8.75 μg/l than that in the group with a CEA level <8.75 μg/l.

CONCLUSIONS

An elevated serum CEA level is common in patients with CADM, and a higher serum CEA level is a powerful indicator of RP-ILD and poor prognosis in those patients.

Clinical characteristics of itch in cutaneous lupus erythematosus: A prospective, multicenter, multinational, cross-sectional study

OBJECTIVE

Pruritus is an important symptom frequently accompanying various inflammatory skin conditions and some recent data indicated that it may be associated with autoimmune connective tissue diseases. The aim of this study was to assess the frequency and clinical presentation of itch in CLE.

METHODS

A multinational, prospective, cross-sectional study was performed to assess the prevalence, intensity and clinical characteristic of pruritus in various subtypes of CLE. A total of 153 patients with active CLE lesions were included. Their age ranged between 17 and 82 years (mean 49.8 ± 15.4 years), and 115 patients (75.2%) were women. The disease activity and damage were assessed according to the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). Pruritus severity was assessed with Numeric Rating Scale (NRS) and the 12-Item Pruritus Severity Scale. Dermatology Life Quality Index and EQ-5D questionnaire were used to measure quality of life.

RESULTS

Pruritus was present in 116 (76.8%) of patients of whom half had NRS scoring equal or above 4 points indicating moderate or severe pruritus. Most commonly itch was localized on the scalp, face (excluding ears and nose) and arms (40.5%, 36.2%, 31.9%, respectively). Sensations connected with pruritus were most frequently described as burning, tingling and like ants crawling feeling, but 31.9% patients described it as "pure itch". More than half of patients reported that pruritus was present every day, and it was most frequent during the evenings. The pruritus scoring and the CLASI activity score were significantly correlated (r = 0.42, p = 0.0001), while no correlation was found with the CLASI damage score (p = 0.16). Both the maximum and average itch intensity were correlated with systemic lupus erythematosus (SLE) activity measured with the Systemic Lupus Erythematosus Disease Activity Index.

CONCLUSIONS

Pruritus is a common, but frequently overlooked symptom of CLE. Its intensity correlates with the activity of CLE, but not with the skin damage. In more than a half of patients it occurs on a daily basis. The correlation between the intensity of pruritus and the activity of the skin lesions and the systemic involvement indicate that pruritus could be an individual indicator of both SLE and CLE activity.

Dermatomyositis and malignancy: should all patients with dermatomyositis undergo malignancy screening?

Dermatomyositis is an autoimmune disease that occurs in association with underlying malignancy in a subset of patients. Given this association, diagnosis of dermatomyositis typically triggers malignancy screening. Although various malignancy screening protocols have been proposed, none have been extensively studied or taken into account prevalence of dermatomyositis-associated malignancies. We utilized peer-reviewed manuscripts identified by a Medline search from May 2000 to April 2020 to present a focused review concerning the association between dermatomyositis and malignancy, and controversies related to screening for malignancies most commonly occurring in dermatomyositis patients. This information was then synthesized to propose a rational strategy for approaching malignancy screening in dermatomyositis patients. Our review supports that risk of malignancy in dermatomyositis patients is well-established. However, the subset of dermatomyositis patients in whom the benefits of malignancy screening outweigh the risks of harm is unknown. Additionally, an evidence-based malignancy screening protocol for dermatomyositis patients that optimizes the risk:benefit ratio does not exist. Given the clear harms that can result, we propose that shared decision-making strategies be implemented to determine whether pursuit of malignancy screening conforms with dermatomyositis patients’ desires and values. Physicians should be clear about potential risks and benefits of malignancy screening, and discuss clinical and serologic features present that may suggest/refute underlying malignancy during conversations aimed at shared decision-making. Research is greatly needed to determine which dermatomyositis patients warrant malignancy screening, which tests should be performed, and the intensity with which they should be ordered. Only after such work is done can malignancy screening in dermatomyositis patients be considered to have high value.

Pruritus in autoimmune connective tissue diseases

Pruritus is one of the most common and bothersome symptoms of skin disorders, and its clinical characteristics and related pathomechanisms have been well described in certain dermatologic conditions, such as atopic dermatitis and urticaria. Although pruritus is believed to be as common in cutaneous autoimmune connective tissue diseases (ACTDs) as in other inflammatory skin disorders, its true characteristics have not been elucidated either qualitatively or quantitatively. Pruritus is present in ACTDs with various prevalence rates, characteristics, and mechanisms depending on the disease types. Pruritus most frequently and severely affects the patients with dermatomyositis, in which itch is strongly correlated with disease activity and severity, thus increased itch could also indicate a disease flare. Patients with other ACTDs, including lupus erythematosus (LE), Sjögren syndrome (SS), morphea, and systemic sclerosis (SSc), also suffer from their fair share of pruritus. Unfortunately, the currently available treatments for ACTDs seem to have only limited and unsatisfactory effects to control pruritus. The extensive impact of pruritus on the patients’ quality of life (QOL) and functioning warrants more targeted and individualized approaches against pruritus in ACTDs. This review will address the prevalence, suggested pathogenesis based on currently available evidences, and potential treatment options of pruritus in various ACTDs of the skin.

Myofascia-dominant involvement on whole-body MRI as a risk factor for rapidly progressive interstitial lung disease in dermatomyositis

OBJECTIVE

Rapidly progressive interstitial lung disease (RPILD) is a major cause of death in patients with DM. Although clinically amyopathic DM (CADM) represents risk for RPILD, the incidence rate of RPILD in patients with CADM varies widely. Whole-body (WB) MRI can reveal involvement of systemic muscle and myofascia. The objective of this study was to explore the risk factors for RPILD in patients with DM using WB-MRI.

METHODS

This retrospective study comprised 41 patients with DM who underwent WB-MRI before the initiation of treatment in our hospital. Muscular and myofascial signals were scored on 42 muscular groups. The myofascia/muscle ratio was calculated and used to define the relevance of myofascia-dominant involvement. RPILD was defined as worsening of dyspnoea, hypoxaemia and radiographic ILD/fibrosis within 3 months from the onset of respiratory symptoms.

RESULTS

Among the 41 patients, 17 had CADM and 30 had ILD, including 10 patients with RPILD. All patients including those with CADM showed abnormal signal intensity in both muscle and myofascia (median score: 15 and 23, respectively). Muscle signal scores positively correlated with the serum creatine kinase level (r = 0.714; P< 0.001). Patients with RPILD showed a significantly higher myofascia/muscle ratio than those without RPILD (1.929 vs 1.200; P= 0.027). Logistic regression analysis identified higher myofascia/muscle ratio as independent risk factors for developing RPILD.

CONCLUSION

Myofascia-dominant involvement was defined and appreciated in patients with DM using WB-MRI. This may be one of the risk factors for RPILD.

A Japanese-American female with rapidly progressive interstitial lung disease associated with clinically amyopathic dermatomyositis

Patients with clinically amyopathic dermatomyositis (CADM) have a risk of developing rapidly progressive interstitial lung disease (ILD). CADM-ILD is associated with the anti-MDA-5 antibody. In the USA, however, patients with CADM have these antibodies less frequently than those in Japan. In addition, those with this disorder are less often complicated with rapidly progressive ILD than those in Japan. We present a case of a 42-year-old Japanese-American female with a 3-month history of a rash on her hands and face with joint pain. Based on the negative results from lupus tests, her primary care provider and a rheumatologist treated her with steroids, hydroxychloroquine, and methotrexate. During treatment, the patient started noticing shortness of breath because of pneumonia, which was revealed by a CT scan. The woman was finally diagnosed with acute respiratory failure due to CADM with ILD. She underwent a double lung transplant as well as treatment with multiple immunosuppressive agents and repeated plasma exchange but died 15 days after transplantation. Her clinical course is similar to that of Japanese patients with CADM-ILD. Outside Japan, primary care providers, rheumatologists, and dermatologists, as well as pulmonary physicians, may be less familiar with this disorder than those in Japan. Since CADM-ILD progresses very quickly and could be fatal, these doctors should be aware of this disease to treat such patients as soon as possible, particularly when seeing a patient of Japanese descent.

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.

Dermatomyositis: An Update on Diagnosis and Treatment

Dermatomyositis is a rare inflammatory disease with characteristic cutaneous findings and varying amounts of systemic involvement. Patients may present with skin disease alone, have concomitant muscle disease, or have extracutaneous manifestations such as pulmonary disease or an associated malignancy. Given such diverse presentations, dermatomyositis is both a diagnostic and therapeutic challenge. However, a prompt diagnosis is of utmost importance to institute adequate therapy and screen patients for an associated malignancy. Dermatologists should play a crucial role in the diagnosis and management of patients with dermatomyositis as cutaneous disease tends to be chronic, negatively impact quality of life, and be more recalcitrant to therapy. In this review, we discuss diagnosis, with a focus on myositis-specific antibodies and their associated phenotypes. We also review therapies available for this often refractory skin disease.

Dermatomyositis: Diagnosis and treatment

The second article in this continuing medical education series reviews the initial evaluation of patients with suspected dermatomyositis (DM), the relevant work-up for malignancy and interstitial lung disease once a diagnosis of DM is made, and treatment recommendations for patients with DM based on disease severity, the presence of systemic symptoms, and myositis-specific antibody (MSA) profiles. This review emphasizes the emerging role of MSAs in the diagnosis of DM and highlights how MSAs can be used to guide the appropriate work-up for malignancy and interstitial lung disease. The treatment approach proposed by this continuing medical education series discusses both established and novel therapies for DM and highlights the importance of considering lesion type, degree of muscle involvement, presence of systemic symptoms, presence of MSAs, and patient age when determining the best treatment approach for a patient with DM.

Pruritus in patients with amyopathic dermatomyositis

Amyopathic dermatomyositis has been associated with the exposure to several drugs: the article by Jeimy et al. described the onset of this uncommon disease in a patient treated with omalizumab. Paradoxically, this patient complained of an intense pruritus and this finding has been reported by several authors observing patients with amyopathic dermatomyositis.

Association of antinuclear antibody status with clinical features and malignancy risk in adult-onset dermatomyositis

BACKGROUND

The clinical significance of antinuclear antibody (ANA) status in adults with dermatomyositis (DM) has yet to be fully defined.

OBJECTIVE

We compared the incidence of amyopathic disease, risk of malignancy, and clinical findings in ANA⁺ and ANA^- patients with adult-onset DM.

METHODS

This was a retrospective cohort study of patients with ANA⁺ or ANA^- adult-onset DM determined by enzyme-linked immunosorbent assay.

RESULTS

Of 231 patients, 140 (61%) were ANA⁺ and 91 (39%) were ANA^-. Compared with the ANA^- patients, the ANA⁺ patients had a lower frequency of dysphagia (15% vs 26% [P = .033]) and heliotrope rash (38% vs 53% [P = .026]). In all, 54 patients (23%) developed malignancy within 3 years of diagnosis of their DM; 11% of the ANA⁺ patients developed malignancy versus 43% of the ANA^- patients (P < .001). There was a strong association between ANA positivity and lower likelihood of malignancy in multivariable analysis (odds ratio, 0.16; P < .001). Conversely, ANA positivity was not associated with amyopathic disease (odds ratio, 0.94; P = .87).

LIMITATIONS

The retrospective nature of the study was a limitation.

CONCLUSION

In patients with adult-onset DM, ANA negativity is associated with increased likelihood of development of malignancy within 3 years of diagnosis of their DM. Particularly close follow-up and frequent malignancy screening may be warranted in ANA^- individuals with DM.

Livedo Racemosa, Reticulated Ulcerations, Panniculitis and Violaceous Plaques in a 46-year-old Woman

Clinically amyopathic dermatomyositis (CADM) is a subset of dermatomyositis (DM) that has conventional cutaneous manifestations of DM, but paradoxically, little or no muscle involvement. In 2005, a novel antibody was described in association with CADM – anti-melanoma differentiation-associated gene 5 (anti-MDA5). Patients with this serologic marker have a characteristic mucocutaneous phenotype consisting of skin ulceration among other signs. We describe the case of a 46-year-old woman with CADM, elevated anti-MDA5 autoantibodies, and unusual clinical features (livedo racemosa, florid acral edema) among the classical phenotype of MDA5 DM (arthralgias, ulcerations, panniculitis) and classical DM lesions (Gottron papules, heliotrope rash). The patients did not develop interstitial lung disease or internal malignancies and experienced a rapid response to prednisolone and intravenous immunoglobulins. After 2 years, she has no relapse of her cutaneous disease and continues 5 mg prednisolone and 2 g/kg kilogram of intravenous immunoglobulin every 3 months for maintenance. Our case highlights the clinical heterogeneity of CADM and underscores the importance of a comprehensive approach to DM patients. It was previously postulated that anti-MDA5 antibody could target vascular cells and compromise vascular function, the presence of livedo racemosa lesions, and MDA5 antibodies in a patient with negative thrombophilia workup, reinforce this idea. This is the first case, to our knowledge, of CADM with acral panniculitis and livedo racemosa.

Updated recommendations on the use of hydroxychloroquine in dermatologic practice

Hydroxychloroquine has unique immunomodulatory properties and an attractive adverse effect profile. Over the past 10 years, research has led to significant updates in clinical recommendations concerning the optimal use of hydroxychloroquine and monitoring of patients taking it. We discuss updated recommendations concerning hydroxychloroquine daily dosing, retinopathy screening, serologic monitoring, use in smokers, use in pregnant women, and adverse effect risk and monitoring. This review can hopefully serve as an aid to dermatologists and help ensure they continue using hydroxychloroquine safely and effectively.

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

Amyopathic dermatomyositis is a rare, idiopathic, connective tissue disease that presents with dermatologic lesions of classic dermatomyositis but lacks the myopathy of this disease. Cutaneous manifestations may include Gottron's sign, heliotrope rash, and characteristic patterns of poikiloderma. There is a substantial risk for developing interstitial lung disease or malignancy in patients with amyopathic dermatomyositis. A literature review of amyopathic dermatomyositis was performed using the PubMed medical database. The key features of amyopathic dermatomyositis, including autoantibodies, clinical presentation and dermatologic manifestations, epidemiology, history, associated malignancies, management, and pathogenesis, are summarized in this review. Cancer (solid tumor) (73/79, 89 %) and hematologic malignancies (9/79, 11 %) were reported in 79 patients, with three patients having more than one malignancy. In addition, there were six patients with amyopathic dermatomyositis who had tumor of unknown primary, and eight patients with cancer-associated amyopathic dermatomyositis for whom no additional details were provided. From the group of 73 tumors for whom primary origin and sex were available, malignancy of the genitourinary organs (24/73, 33 %), aerorespiratory organs (15/73, 21 %), and breast (14/73, 19 %) were the most commonly observed solid organ tumors. Tumors of the genitourinary organs (15/48, 31 %) and breast (14/48, 29 %) were the most frequent neoplasms in women, accounting for 29 of 48 (60 %) cancers, with the most common sites being breast (14/48, 29 %), ovary (8/48, 17 %), and cervix or uterus (5/48, 10 %). In men, tumors of the aerorespiratory (9/25, 36 %) and genitourinary (9/25, 36 %) tracts were the most common neoplasms, accounting for 72 % (18/25) of cancers; the most common sites of primary malignancy were nasopharyngeal (6/25, 24 %), bladder (4/25, 16 %), and either colorectal, lung or prostate cancer (three cancers each, 12 %). In summary, the search for an undiagnosed associated malignancy in patients with amyopathic dermatomyositis should focus towards the organs most frequently affected. Similar to classic dermatomyositis, ovarian and nasopharyngeal cancers are also common in amyopathic dermatomyositis. However, in contrast to lung cancer, which is the most frequent malignancy associated with classic dermatomyositis, breast cancer was the most common type of malignancy reported in patients with amyopathic dermatomyosotis.