A new proposal for phenotypic classification and outcome assessment of dermatomyositis based on clinical manifestations and serological testing

BACKGROUND

Dermatomyositis (DM) is an infrequent disease subgroup of idiopathic inflammatory myopathies characterized by distinct skin lesions. However, high heterogeneity makes clinical diagnosis and treatment of DM very challenging.

OBJECTIVES

Unsupervised classification in DM patients and analysis of key factors related to clinical outcomes.

METHODS

This retrospective study was conducted between 2017 and 2022 at the Department of Rheumatology, Xiangya Hospital, Central South University. 162 DM patients were enrolled for unsupervised hierarchical cluster analysis. In addition, we divided the clinical outcomes of DM patients into four subgroups: withdrawal, stabilization, aggravation, and death, and compared the clinical profiles amongst the subgroups.

RESULTS

Out of 162 DM patients, three clusters were defined. Cluster 1 (n = 40) was mainly grouped by patients with prominent muscular involvement and mild Interstitial Lung Disease (ILD). Cluster 2 (n = 72) grouped patients with skin rash, anti-Melanoma Differentiation Associated protein 5 positive (anti-MDA5+), and Rapid Progressive Interstitial Lung Disease (RP-ILD). Cluster 3 (n = 50) grouped patients with the mildest symptoms. The proportion of death increased across the three clusters (cluster 3 < cluster 1 < cluster 2).

STUDY LIMITATIONS

The number of cases was limited for the subsequent construction and validation of predictive models. We did not review all skin symptoms or pathological changes in detail.

CONCLUSIONS

We reclassified DM into three clusters with different risks for poor outcome based on diverse clinical profiles. Clinical serological testing and cluster analysis are necessary to help clinicians evaluate patients during follow-up and conduct phenotype-based personalized care in DM.

Association between clinical phenotypes of dermatomyositis and polymyositis with myositis-specific antibodies and overlap systemic autoimmune diseases

The aim of this study was to evaluate the association between clinical phenotypes of dermatomyositis (DM) and polymyositis (PM) with myositis-specific antibodies (MSAs), and overlap diagnosis of systemic autoimmune diseases.This cross-sectional study was conducted on 67 patients with DM and 27 patients with PM recruited from a regional hospital in southern Taiwan. Clinical phenotypes of DM and PM were assessed and MSAs were measured using a commercial line blot assay. The association of clinical phenotypes of DM and PM with MSAs and overlap diagnosis of systemic autoimmune diseases was performed using univariate and multiple logistic regression analyses.Clinically, patients with DM and PM and overlap diagnosis of systemic sclerosis were associated with a higher risk of interstitial lung diseases (ILDs) (odds ratio [OR] = 6.73; P = .048), Raynaud phenomenon (OR = 7.30; P = .034), and malignancy (OR = 350.77; P = .013). The risk of malignancy was also associated with older age (OR 1.31; P = .012), and male patients were associated with a higher risk of fever. For MSAs, anti-aminoacyl-tRNA synthetase antibodies were associated with ILD, antinuclear antibody were associated with a lower risk of arthritis, anti-transcription intermediary factor 1-gamma antibodies were associated with milder symptoms of muscle weakness, anti-Ku antibodies were associated with overlap diagnosis of systemic lupus erythematosus, and anti-Ro52 antibodies were associated with the development of Raynaud phenomenon and Sjögren syndrome.MSAs and overlap diagnosis of systemic sclerosis were significantly associated with clinical phenotypes of DM and PM. Physicians should be vigilant for malignancy in older DM and PM patients with overlap diagnosis of systeic sclerosis. The possibility of developing ILD in patients with overlap diagnosis of systemic sclerosis or serum positivity of anti-aminoacyl-tRNA synthetase antibodies should be considered.

Different phenotypes in dermatomyositis associated with anti-MDA5 antibody: Study of 121 cases

OBJECTIVES

The predominance of extramuscular manifestations (e.g., skin rash, arthralgia, interstitial lung disease [ILD]) as well as the low frequency of muscle signs in anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5+) dermatomyositis caused us to question the term myositis-specific antibody for the anti-MDA5 antibody, as well as the homogeneity of the disease.

METHODS

To characterize the anti-MDA5+ phenotype, an unsupervised analysis was performed on anti-MDA5+ patients (n = 83/121) and compared to a group of patients with myositis without anti-MDA5 antibody (anti-MDA5-; n = 190/201) based on selected variables, collected retrospectively, without any missing data.

RESULTS

Within anti-MDA5+ patients (n = 83), 3 subgroups were identified. One group (18.1%) corresponded to patients with a rapidly progressive ILD (93.3%; p < 0.0001 across all) and a very high mortality rate. The second subgroup (55.4%) corresponded to patients with pure dermato-rheumatologic symptoms (arthralgia; 82.6%; p < 0.01) and a good prognosis. The third corresponded to patients, mainly male (72.7%; p < 0.0001), with severe skin vasculopathy, frequent signs of myositis (proximal weakness: 68.2%; p < 0.0001), and an intermediate prognosis. Raynaud phenomenon, arthralgia/arthritis, and sex permit the cluster appurtenance (83.3% correct estimation). Nevertheless, an unsupervised analysis confirmed that anti-MDA5 antibody delineates an independent group of patients (e.g., dermatomyositis skin rash, skin ulcers, calcinosis, mechanic's hands, ILD, arthralgia/arthritis, and high mortality rate) distinct from anti-MDA5- patients with myositis.

CONCLUSION

Anti-MDA5+ patients have a systemic syndrome distinct from other patients with myositis. Three subgroups with different prognosis exist.

Cutaneous dermatomyositis disease course followed over time using the Cutaneous Dermatomyositis Disease Area and Severity Index

BACKGROUND

Limited studies describe the longitudinal course of cutaneous dermatomyositis (DM).

OBJECTIVE

To characterize disease course in treated cutaneous DM by using the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), a validated outcome instrument.

METHODS

A retrospective cohort included patients with DM who had their CDASI activity subscore recorded for at least 2 years. Disease progression was classified as improved, worsened, or stable, and disease course was classified as monophasic, polyphasic, or chronic. Subjects were divided into groups with disease of mild (n = 16) and moderate-to-severe (n = 24) baseline severity.

RESULTS

A total of 40 patients with DM met inclusion criteria. The majority demonstrated improvement in disease activity (n = 21 [52.5%]) rather than worsening (n = 7 [17.5%]) and stable (n = 12 [30.0%]) disease. Most patients with mild disease remained stable (n = 10 [62.5%]), whereas most with moderate-to-severe disease improved (n = 19 [79.2%]). A polyphasic course (n = 33 [82.5%]) predominated over monophasic (n = 5 [12.5%]) and chronic (n = 2 [5%]) courses. The average number of flares per year per number of years of follow-up was independent of baseline disease activity.

LIMITATIONS

The retrospective design, potential referral bias, and cutoff values in classification criteria are limitations.

CONCLUSION

Baseline CDASI activity score is associated with particular patterns of disease course and progression in cutaneous DM.

Cutaneous signs of classical dermatomyositis

Idiopathic immune myopathies (IIM) are an heterogeneous group of autoimmune muscle disorders characterized by progressive muscle involvement. Dermatomyositis (DM) is the most common form of IIM. It is a multisystem disorder characterized by symmetric proximal, extensor, inflammatory myopathy, vascular involvement and a characteristic cutaneous eruption. Six types of DM have been identified: idiopathic, juvenile (JDM), cancer-related other autoimmune diseases-related, iatrogenic DM and amyopathic DM. Cutaneous manifestations of DM are the most important aspect of this disease and can precede from several months to years muscle or systemic involvement. Three groups of signs have been described: pathognomonic, highly characteristic and compatible. Although differences exist among the different clinical presentation of skin lesions, they share common histological findings including the presence of interface dermatitis with epidermal atrophy, basement membrane degeneration, vacuolar alteration of basal keratinocytes, and dermal changes consisting of interstitial mucin deposition and a sparse lymphocytic infiltrate. DM is a serious disease; the correct evaluation of any skin lesion suggesting an early diagnosis is of utmost importance. Skin signs may, also, represent a marker of treatment efficacy even though systemic symptoms worsening may not always be followed by more severe skin lesions.

Classifying idiopathic inflammatory myopathies: comparing the performance of six existing criteria

OBJECTIVES

Various criteria have been proposed to classify the inflammatory myositides (IIMs) polymyositis (PM) and dermatomyositis (DM). However, none have received universal acceptance. Our aim was to assess the performance of the main criteria used to classify IIM. Specialist consultant diagnosis was considered the gold standard.

METHODS

Patients attending King's College Hospital (KCH) or Reggio Emilia Hospital (REH) since 1990 with a diagnosis of IIM or non-inflammatory myopathy were identified, and their records and laboratory investigations retrospectively reviewed. Where the complete data required for the classification criteria or a final physician diagnosis was unavailable, patients were excluded. 52 patients with a specialist diagnosis of PM, DM, inclusion body myositis (IBM) or non-inflammatory myopathy were included. Agreement between specialist consultant diagnosis and classification criteria was measured using Cohen's kappa (κ) statistics. Sensitivity and specificity were also calculated.

RESULTS

The Dalakas (2003) criteria demonstrated substantial agreement with specialist diagnosis: κ=0.69, sensitivity 77%, specificity 99%. The European Neuromuscular Centre criteria (ENMC) demonstrated fair agreement: κ=0.49, sensitivity 71%, specificity 82%. Other criteria performed less well. In particular, the Bohan and Peter criteria demonstrated a specificity of only 29%.

CONCLUSIONS

The criteria of Dalakas (2003) agreed best with specialist consultant diagnosis. The criteria of Bohan and Peter demonstrated very poor specificity. Prospective studies are required to develop improved classification criteria.

Polymyositis, dermatomyositis, and autoimmune necrotizing myopathy: clinical features

Idiopathic inflammatory myopathies are a heterogeneous group of autoimmune disorders predominantly affecting skeletal muscles, resulting in muscle inflammation and weakness. The 3 most common inflammatory myopathies are polymyositis (PM), dermatomyositis (DM), and inclusion body myositis. This review details the clinical findings noted in PM, DM, and the emerging entity of autoimmune necrotizing myopathy.

Malignancy is associated with dermatomyositis but not polymyositis in Northern New England, USA

OBJECTIVE

To retrospectively evaluate the association of idiopathic inflammatory myopathy (IIM) and malignancy in patients seen at 1 academic center over a 23-year period.

METHODS

Patients were identified using the International Classification of Diseases, 9th edition (ICD-9) codes and diagnoses, then confirmed by chart review. Population cancer statistics obtained from the US Centers for Disease Control for Vermont and New Hampshire were used for comparison.

RESULTS

Chart review confirmed IIM in 198 of 483 patients initially identified by ICD-9 codes. Within 5 years of diagnosis with IIM, malignancy developed in 32 patients (16.2%), 24 of whom (75%) had dermatomyositis (DM). Malignancy and DM developed within 1 year in 75%. The cancer risk associated with DM was much greater than the risk associated with other IIM. The most frequent tumor types were breast, lung, pancreas, and colon. DM patients with cancer were more frequently male and >or= 45 years of age than those without cancer. There were no cases of interstitial lung disease among patients with cancer and any form of IIM. The incidence of cancer was increased in patients with DM compared to age- and sex-matched population controls, both over a 5-year interval surrounding the diagnosis of DM and over the lifetime interval following diagnosis.

CONCLUSION

The risk of cancer in IIM is concentrated among patients with DM. The association between DM and cancer was enhanced by its temporal relationship (< 1 year) in 87.5% of these cases. Patients with malignancy-associated DM were more frequently male and over age 45 and less likely to have interstitial lung disease.

A Brazilian registry of juvenile dermatomyositis: onset features and classification of 189 cases

OBJECTIVE

To describe onset features, classification and treatment of juvenile dermatomyositis (JDM) and juvenile polymyositis (JPM) from a multicentre registry.

METHODS

Inclusion criteria were onset age lower than 18 years and a diagnosis of any idiopathic inflammatory myopathy (IIM) by attending physician. Bohan & Peter (1975) criteria categorisation was established by a scoring algorithm to define JDM and JPM based on clinical protocol data.

RESULTS

Of the 189 cases included, 178 were classified as JDM, 9 as JPM (19.8: 1) and 2 did not fit the criteria; 6.9% had features of chronic arthritis and connective tissue disease overlap. Diagnosis classification agreement occurred in 66.1%. Median onset age was 7 years, median follow-up duration was 3.6 years. Malignancy was described in 2 (1.1%) cases. Muscle weakness occurred in 95.8%; heliotrope rash 83.5%; Gottron plaques 83.1%; 92% had at least one abnormal muscle enzyme result. Muscle biopsy performed in 74.6% was abnormal in 91.5% and electromyogram performed in 39.2% resulted abnormal in 93.2%. Logistic regression analysis was done in 66 cases with all parameters assessed and only aldolase resulted significant, as independent variable for definite JDM (OR=5.4, 95%CI 1.2-24.4, p=0.03). Regarding treatment, 97.9% received steroids; 72% had in addition at least one: methotrexate (75.7%), hydroxychloroquine (64.7%), cyclosporine A (20.6%), IV immunoglobulin (20.6%), azathioprine (10.3%) or cyclophosphamide (9.6%). In this series 24.3% developed calcinosis and mortality rate was 4.2%.

CONCLUSION

Evaluation of predefined criteria set for a valid diagnosis indicated aldolase as the most important parameter associated with definite JDM category. In practice, prednisone-methotrexate combination was the most indicated treatment.

Vesiculo-bullous dermatomyositis: report of three cases

Dermatomyositis (DM) presents with various types of skin lesions, but vesicle formation is rare. We herein present three female patients with DM who formed vesicles on the trunk and extremities. In all cases the bullous lesions appeared in parallel with increased disease activity of DM. In one case, only one large bulla within an erythematous background was found on the abdomen; the other two cases presented with a number of vesicles. Histological examination revealed marked subepidermal edema with mucin deposition in the upper dermis in all cases. Breast carcinoma and malignant lymphoma were associated in one case each. However, investigations did not reveal any malignancies in the third case. Prior reports suggest that internal malignancy is much higher in patients with vesiculo-bullous DM than in those unassociated with bullous lesions. Clinicians should be aware of vesiculo-bullous type DM.

Review of the classification and assessment of the cutaneous manifestations of the idiopathic inflammatory myopathies

Adult and juvenile dermatomyositis, polymyositis and myositis overlapping with another connective tissue disease are rare systemic autoimmune diseases with a primary feature of weakness and muscle inflammation. Cutaneous findings specific to the underlying condition are present in many patients with these disorders. Some lesions are highly characteristic of the idiopathic inflammatory myopathies (IIM), especially in dermatomyositis. Some cutaneous findings are common but not specific to the IIM and others are less frequently observed in patients with these illnesses. Many of these manifestations also have different grades of disease activity or damage. This photoessay reviews the classification and assessment of the cutaneous manifestations of the IIM and presents example photographs of many of the lesions of adult and juvenile IIM accumulated from the clinical experience of international experts in these conditions. The purpose of this work is to facilitate better recognition of the diverse cutaneous manifestations associated with these inflammatory myopathies.

[Juvenile dermatomyositis presenting with anasarca: a possible new variant]

Juvenile dermatomyositis is a rare autoimmune disease characterized by inflammation of the muscle skin and other organs. Although localized edema is a common feature of juvenile dermatomyositis generalized edema has been reported infrequently. We describe a patient with dermatomyositis and anasarca and present a brief review of the literature.

Number, characteristics, and classification of patients with dermatomyositis seen by dermatology and rheumatology departments at a large tertiary medical center

BACKGROUND

The current diagnostic criteria for dermatomyositis (DM) exclude patients without muscle involvement. As a result there is a paucity of research related to the complete spectrum of the disease.

OBJECTIVE

The goal of this study was to evaluate differences in the clinical manifestations of DM seen by dermatology relative to rheumatology. We hypothesized that patients with minimal (hypomyopathic) or no (amyopathic) muscle disease would more likely be seen in dermatology, whereas those with more severe (classic) muscle disease would be seen in rheumatology.

METHODS

We performed a retrospective chart review of patients with DM seen by our dermatology and rheumatology departments to classify spectrum, presentation, and complications. Patients seen between July 1, 2003, and June 30, 2006, were identified by Current Procedural Terminology billing code 710.3. Patients with mixed connective tissue diseases or miscoded DM were excluded.

RESULTS

In all, 131 (65%) patients seen in dermatology, 58 (29%) in rheumatology, and 13 (6%) in both departments were identified. In all, 83 (69%) patients seen in dermatology, 27 (23%) in rheumatology, and 10 (8%) in both departments met criteria for inclusion in the study. The number of patients seen in rheumatology given the classification of classic DM (CDM) (24 of 27 [89%]), hypomyopathic DM (2 of 27 [7%]), and amyopathic DM (ADM) (1 of 27 [4%]) differed significantly from dermatology, where CDM comprised 27 of 83 (33%), hypomyopathic DM comprised 23 of 83 (28%), and ADM comprised 33 of 83 (40%) of the population, respectively (P < .001). Sex, ethnicity, and rates of interstitial lung disease differed between departments. There was no difference in the rates of interstitial lung disease between CDM and ADM (P = .30). The degree of muscle involvement did not correlate with the rates of DM-associated malignancy (P = .57). Few patients with ADM had muscle biopsy (n = 1) or electromyography (n = 7) testing. Positive anti-Jo-1 was seen in 2 of 96 patients (2%; one CDM and one ADM, both with interstitial lung disease), reflecting an overall low prevalence of this autoantibody, or a potential problem with the laboratory assay.

LIMITATIONS

Patients reflect the population in only one institution and, thus, the results may not be generalizable to other settings or referral centers. Because this is a retrospective chart review, results are limited by missing data and nonstandardized physical examinations and laboratory data across patients and physicians.

CONCLUSIONS

There is a clear difference in DM presentation to dermatology and rheumatology by degree of myositis-complicated disease.

International consensus on a proposed score system for muscle biopsy evaluation in patients with juvenile dermatomyositis: A tool for potential use in clinical trials

OBJECTIVE

To devise and test a system with which to evaluate abnormalities on muscle biopsy samples obtained from children diagnosed with juvenile dermatomyositis (DM).

METHODS

We established an International Consensus Group on Juvenile DM Biopsy and carried out 2 phases of consensus process and scoring workshops. Biopsy sections (n = 33) were stained by standard methods. The scoring tool was based on 4 domains of change: inflammatory, vascular, muscle fiber, and connective tissue. Using a Latin square design, biopsy samples were scored by 11 experts for items in each domain, and for a global abnormality measure using a 10-cm visual analog score (VAS 0-10). The tool's reliability was assessed using an intraclass correlation coefficient (ICC) and scorer agreement (alpha) by determining variation in scorers' ratings.

RESULTS

There was good agreement in many items of the tool, and several items refined between the meetings improved in reliability and/or agreement. The inflammatory and muscle fiber domains had the highest reliability and agreement. The overall VAS score for abnormality had high agreement and reliability, reaching an ICC of 0.863 at the second consensus meeting.

CONCLUSION

We propose a provisional scoring system to measure abnormalities on muscle biopsy samples obtained from children with juvenile DM. This system needs to be validated, and then could be used in prospective studies to test which features of muscle pathology are prognostic of disease course or outcome. We suggest that the process we used could be a template for developing similar systems in other forms of myositis.

In adult onset myositis, the presence of interstitial lung disease and myositis specific/associated antibodies are governed by HLA class II haplotype, rather than by myositis subtype

The aim of this study was to investigate HLA class II associations in polymyositis (PM) and dermatomyositis (DM), and to determine how these associations influence clinical and serological differences. DNA samples were obtained from 225 UK Caucasian idiopathic inflammatory myopathy patients (PM = 117, DM = 108) and compared with 537 randomly selected UK Caucasian controls. All cases had also been assessed for the presence of related malignancy and interstitial lung disease (ILD), and a number of myositis-specific/myositis-associated antibodies (MSAs/MAAs). Subjects were genotyped for HLA-DRB1, DQA1 and DQB1. HLA-DRB1*03, DQA1*05 and DQB1*02 were associated with an increased risk for both PM and DM. The HLA-DRB1*03-DQA1*05-DQB1*02 haplotype demonstrated strong association with ILD, irrespective of myositis subtype or presence of anti-aminoacyl-transfer RNA synthetase antibodies. The HLA-DRB1*07-DQA1*02-DQB1*02 haplotype was associated with risk for anti-Mi-2 antibodies, and discriminated PM from DM (odds ratio 0.3, 95% confidence interval 0.1-0.6), even in anti-Mi-2 negative patients. Other MSA/MAAs showed specific associations with other HLA class II haplotypes, irrespective of myositis subtype. There were no genotype, haplotype or serological associations with malignancy. The HLA-DRB1*03-DQA1*05-DQB1*02 haplotype associations appear to not only govern disease susceptibility in Caucasian PM/DM patients, but also phenotypic features common to PM/DM. Though strongly associated with anti-Mi-2 antibodies, the HLA-DRB1*07-DQA1*02-DQB1*02 haplotype shows differential associations with PM/DM disease susceptibility. In conclusion, these findings support the notion that myositis patients with differing myositis serology have different immunogenetic profiles, and that these profiles may define specific myositis subtypes.

A systematic review of adult-onset clinically amyopathic dermatomyositis (dermatomyositis siné myositis): a missing link within the spectrum of the idiopathic inflammatory myopathies

OBJECTIVE

Classical dermatomyositis (CDM) patients display the hallmark cutaneous manifestations of dermatomyositis (DM), proximal muscle weakness, and laboratory evidence of myositis. The epidemiology and management of both adult-onset and juvenile-onset CDM has been well characterized. However, the clinical significance of the hallmark inflammatory cutaneous manifestations of DM occurring in individuals who have no clinically significant muscle weakness and normal muscle enzymes for prolonged periods of time (ie, 6 months or longer) has not been clear. The term amyopathic DM (ADM) (synonymous with DM siné myositis) has been proposed to draw attention to such individuals. A related form of DM, "hypomyopathic DM" [HDM], is the presence of DM skin disease for 6 months or longer in individuals who have no muscle weakness but who are found to have some evidence of muscle inflammation upon testing (muscle enzyme levels, electromyogram, muscle biopsy, muscle magnetic resonance imaging [MRI]). Clinically amyopathic DM (CADM) is a designation that has been proposed for patients having either ADM or HDM. The clinically amyopathic component of this designation was coined to emphasize the fact that the only clinical problem being experienced by these patients at the time of diagnosis is their DM skin disease. Our personal experience suggests that the CADM subphenotype might be more prevalent in adults than has been thought previously. To test this hypothesis and address questions relating to the optimal management and prognosis of such patients, we have systematically reviewed the published literature in this area.

METHODS

We carried out a systematic review of the published literature on adult-onset CADM as defined in Table 1 through May 1, 2004.

RESULTS

We identified 291 adult-onset CADM cases (18 years or older) reported from over 19 countries. The average duration of DM skin disease was 3.74 years (range, 6 months [by definition] to > 20 years), and 73% were female. Among 37 patients with HDM who were identified, the average duration of disease was 5.4 years, and none had developed clinically significant weakness at the time of the reports. Thirty-seven of the reported CADM patients developed muscle weakness greater than 6 months after onset of their skin disease (15 months to 6 years). For the sake of this discussion, such patients have been analyzed under the designation of "CADM --> CDM." Somewhat surprisingly, 36/291 (13%) of the identified published CADM patients developed interstitial lung disease. Incidental to our review, we also identified 10 published cases of individuals having DM skin disease and interstitial lung disease without muscle weakness, 7 of whom died from interstitial lung disease less than 6 months after onset of their DM skin disease (the term pre-myopathic DM coined by others has been used here to refer to such patients). In addition, an associated internal malignancy was found in 41/291 (14%) of the identified CADM cases. A positive antinuclear antibody was reported in 63% and myositis-specific autoantibodies (eg, Jo-1, Mi-2) in only 3.5% of the reported CADM patients in which such data were available.

CONCLUSIONS

The results of this analysis suggests that the CADM subphenotype is more common than has been thought previously and that such patients may comprise a relatively high proportion of DM patients followed by dermatologists. Some CADM patients also have been observed to develop overt proximal muscle weakness years after onset of their DM skin disease. In addition, CADM patients appear to be at risk of developing the same potentially fatal disease associations/complications for which CDM patients are at risk (eg, interstitial lung disease and internal malignancy). Population-based studies of the epidemiology and optimal management of CADM patients, including efforts to identify risk factors associated with potentially fatal outcomes such as late-onset muscle weakness, interstitial lung disease, and malignancy, are needed. As an incidental finding to this literature review, we also identified a small number of reported cases of often-fatal interstitial lung disease occurring shortly after the onset of DM skin disease (< 6 months) in the complete absence of muscle weakness. This subphenotype, referred to as "pre-myopathic DM," is one with which dermatologists should be aware as early diagnosis and aggressive management can be lifesaving.

Novel classification of idiopathic inflammatory myopathies based on overlap syndrome features and autoantibodies: analysis of 100 French Canadian patients

Our objective was to improve the currently imperfect classifications of idiopathic inflammatory myopathies (IIM). In clinical practice, overlap features are common in IIM. This provided a rationale for positioning overlap clinical features at the core of a new classification system. We conducted a longitudinal study of 100 consecutive adult French Canadian patients with IIM. Clinical and laboratory data were obtained by retrospective chart review. Sera were analyzed for autoantibodies (aAbs) by protein A-assisted immunoprecipitation and double immunodiffusion. Overlap aAbs encompassed aAbs to synthetases, systemic sclerosis-associated aAbs, anti-signal recognition particle (SRP) and anti-nucleoporins. Patients were classified both at IIM diagnosis, based on data at presentation, and at the end of follow-up, based on cumulative findings. Three classifications were used: 1) the Bohan and Peter original classification, 2) a new version of that classification as modified by us, and 3) a novel clinicoserologic classification. As investigators were blinded to aAb results, the modified classification is strictly a clinical classification. Its core concept is the attribution of diagnostic significance to the presence of overlap features, that is, their presence resulted in a diagnosis of overlap myositis (OM). This approach allowed direct comparison with the original Bohan and Peter classification. By integrating aAb results to the modified classification, we also defined the clinicoserologic classification, which allowed to examine the added value of aAbs to diagnostic, therapeutic and prognostic stratification. Whereas polymyositis (PM) was the most common IIM according to the original classification, accounting for 45% of the cohort at diagnosis, its frequency fell to 14% with the modified classification. Conversely, while the frequency of myositis associated with connective tissue disease was 24% according to the original classification, the frequency of OM was 60% when using the modified classification. At last follow-up, the frequency of PM fell further to only 9%, while the frequency of OM rose to 67%. Systemic sclerosis was the most common connective tissue disease associated with IIM, accounting for 42.6% of OM patients and 29% of the cohort. The frequencies of overlap aAbs in the cohort and in OM patients were 48% and 70.5% (n =48/68), respectively. The presence of overlap aAbs at IIM diagnosis identified additional OM patients unrecognized by the modified classification. The sensitivity of the modified classification for OM at diagnosis was 87%, suggesting that clinicians may rely on the modified classification for identification of most OM patients, while awaiting results of aAb assays. The new classifications predicted the response to prednisone and IIM course. Using stringent definitions, IIM was classified as responsive or refractory after an adequate initial corticosteroid therapy, and the disease course as monophasic or chronic after a single adequate trial of prednisone. PM was always chronic and was associated with the highest rate (50%) of refractoriness to initial corticosteroid treatment. Dermatomyositis was almost always chronic (92% rate); however, its responsiveness to initial corticosteroid treatment was high (87%). OM was almost always responsive to corticosteroids (89%-100% rates). When OM patients were divided according to aAb subsets, anti-synthetase, SRP, or nucleoporin aAbs were markers for chronic myositis, whereas aAbs to U1RNP, Pm-Scl, or Ku were markers for monophasic myositis. We conclude that the original Bohan and Peter classification should be abandoned as it leads to misclassification of patients. Much of IIM is composed of OM. The proposed modified and clinicoserologic classifications have diagnostic, prognostic, and therapeutic value.

Skin involvement in dermatomyositis

PURPOSE OF REVIEW

Dermatomyositis (DM) is a rare multisystem autoimmune disorder of adults and children that primarily affects skin and skeletal muscle. Classification systems of dermatomyositis, polymyositis, and the other idiopathic inflammatory myopathies focus primarily on features of muscle involvement. However, cutaneous disease does not always parallel muscle disease in its onset, activity, or response to therapy. This review will describe the distinct cutaneous clinical and histopathologic presentation of DM and the relation between these cutaneous findings, pathogenesis of DM, and serological subsets of DM.

RECENT FINDINGS

This review discusses recent findings that have begun to elucidate the pathogenesis of DM, including polymorphism of tumor necrosis factor-alpha 308A allele and maternal fetal microchimerism. The recent description of other systemic diseases and drugs causing DM-like eruptions and the recognition that DM can resemble other common dermatoses highlights the need for a cutaneous biopsy to diagnose and distinguish the cutaneous features of DM. Once diagnosed, a number of noninvasive imaging modalities and new cutaneous assessment instruments can be used to follow and evaluate patients with DM.

SUMMARY

Recognition of cutaneous and histopathologic findings in DM is essential for prompt and accurate diagnosis and treatment of DM.

[Polymyositis, dermatomyositis and inclusion body myositis, nosological aspects]

THREE GROUPS OF PRIMARY INFLAMMATORY MUSCLE DISEASES: The primary inflammatory muscle diseases comprise three main subsets: polymyositis (PM), dermatomyositis (DM) and inclusion body myositis (IBM). PM and DM are characterized by a proximal weakness that develops along weeks to months and by elevated creatine phosphokinase levels. Cutaneous involvement including both erythema and edema and infantile or adult onset are DM specific. PM and IBM only concern adults. Several PM/DM manifestations must be searched for because of their severity: swallowing disorders, various mechanisms of respiratory dysfunction (swallowing pneumopathies, interstitial lung disease, respiratory muscle deficiency) and cardiac involvement. DIAGNOSTIC ELEMENTS FOR PM AND DM: Two investigations, beside biopsy, are particularly useful: muscle MRI imaging showing inflammatory pattern and specific detection of antisynthetase autoantibodies (PM/DM with interstitial lung disease) and anti-Mi-1 and 2 in DM. PHYSIOPATHOLOGICAL DATA: PM and DM differ in their histological and physiopathological characteristics: perivascular B and CD4 lymphocyte infiltrates and complement deposits at the origin of humoral induced vascular disease in DM and perimysial CD8 lymphocytes inducing a cellular mediated cytotoxic injury in PM. Class I HLA antigen expression on the muscle fibers and production of cytokines play a crucial role in the pathogenesis of these two diseases. PM and DM may be associated with cancers, connective-tissue disease (overlap syndrome). Some PM are secondary to HIV, HTLV1 virus and toxoplasmosis infection. CHARACTERISTICS OF INCLUSION BODY MYOSITIS: IBM, the most frequent acquired myopathy after 50 years of age, is characterized by particular features: not only clinical (late onset, selective weakness, early distal involvement, slow course, unresponsiveness to corticosteroid and immunosuppressant agents); but also histological (rimmed vacuoles, filamentous inclusions) and pathogenic (cytotoxic and degenerative inflammatory process, similar to Alzheimer's disease, with beta-amyloid protein accumulation).

Idiopathic inflammatory myopathies: epidemiology, classification, and diagnostic criteria

Epidemiologic studies have helped to define the prevalence and incidence of PM, DM, and IBM and have highlighted differences in risk between men and women and in the age at onset for the different forms of myositis. Additionally, these studies have shown that there is a substantially higher risk of PM and DM in certain racial groups which is likely to be genetically determined. These differences are all likely to be fundamental in terms of the pathogenesis of these diseases but, as yet, their full significance remains uncertain. They do, however, suggest that the interplay between genetic and environmental initiating factors is different in the three disorders. Additional population-based studies in homogeneous racial groups, in parallel with studies of susceptibility genes for autoimmune disease, such as those encoding the MHC and inflammatory cytokines, are needed to throw further light on the role of genetic factors in the pathogenesis of the IIMs [47]. Because of the paucity of epidemiologic data on IBM, further studies are required to determine the degree of variation in prevalence in different populations and racial groups, as well as the consistency of the male association and age spectrum of manifestations of the disease. The particularly strong association with DR3 in this form of IIM [48] clearly points to the importance of genetic factors in pathogenesis, but further studies of DR3-associated genes in the MHC and of other candidate genes are needed to define more precisely the genes that convey susceptibility to the disease in different racial groups. Epidemiologic studies also have the potential to identify environmental factors that may play a part in disease initiation in genetically susceptible individuals. Seasonal patterns of disease onset have been reported, particularly in patients with DM [49-51] as well as seasonal variation in the frequency of relapses [52], pointing to the probable involvement of intercurrent infections, ultraviolet light exposure, or other environmental factors in disease initiation and reactivation. Further prospective studies are required to determine the contribution of environmental exposures and how they interact with genetic susceptibility factors to lead to myositis. One of the major limitations of a number of the previous epidemiologic studies is the lack of precision in the diagnostic criteria used and the classification of cases of IIM. The Bohan and Peter criteria [1] which were used in most studies after 1975, were introduced before IBM was recognized as an entity distinct from PM; most of the published incidence and prevalence figures for PM are therefore likely to be inaccurate. Multicentered, interdisciplinary, prospective studies, incorporating comprehensive clinical, laboratory, and pathologic information, are needed to develop and validate better diagnostic and classification criteria and to determine the true prevalence and incidence of the many forms of IIM.

Dermatomyositis: an overview of recent progress with emphasis on dermatologic aspects

Important points regarding DM and C-ADM are as follows: C-ADM is a working functional designation for patients having the skin-only and skin-predominant subsets of DM, amyopathic DM, and hypomyopathic DM. C-ADM seems to have approximately 10% the incidence of classic DM in whites and possibly a higher incidence in Asians. Some patients who present with C-ADM, with or without subclinical laboratory abnormalities, can slowly progress to develop symptomatic muscle weakness over a period of years, whereas others go for 10 to 20 years and longer without the appearance of muscle weakness. C-ADM patients are at risk for potentially life-threatening complications of classic DM, such as interstitial lung disease, which may occur in up to 10% of C-ADM patients. This risk seems to be even greater in some ethnic subgroups (e.g., Japanese). C-ADM patients may also be at increased risk for internal malignancy and until further studies are carried out to confirm the statistical significance of this association, all such patients should have a thorough evaluation for internal malignancy, identical to the approach currently used in classic DM patients. Dermatologists are in the best position initially to diagnose C-ADM patients and can contribute greatly to their overall management and quality of life. Ongoing vigilance is required, however, for complications that can arise in C-ADM patients including potentially fatal interstitial lung disease, internal malignancy, delayed onset of muscle weakness from myositis, and complications of systemic drug therapy. Topical therapy with broad-spectrum sunscreens, anti-inflammatories, and antipruritics should be maximized during the initial management of the cutaneous manifestations of either classic DM or C-ADM. Single-agent or combined aminoquinoline antimalarial therapy represents the safest initial form of systemic therapy for DM-specific skin disease occurring in any clinical setting; however, this approach tends to be less effective in general than for cutaneous LE. There is a theoretical rationale for and limited preliminary successful anecdotal experience with the use of anti-TNF-alpha therapy in refractory cases of classic DM and C-ADM. Cautious systematic clinical trials in this area should be considered.

Amyopathic dermatomyositis: retrospective review of 37 cases

Criteria for diagnosis of amyopathic dermatomyositis vary, and the prognosis is not clear. Our purpose was to investigate prognosis regarding progression to myositis and associated malignancy. We reviewed the medical records of patients with dermatomyositis evaluated at our institution from 1976 to 1994. Of 746 patients with dermatomyositis, 37 (5%) with the amyopathic subtype were divided into 3 groups: group 1 (73%), no subjective or objective evidence of myopathy; group 2 (13%), no subjective muscle weakness but abnormalities detected by objective tests; group 3 (13%), subjective muscle weakness but no objective evidence of myopathy. Follow-up was conducted by means of a mailed questionnaire. For 25 patients, follow-up of 1 to 17 years after diagnosis showed muscle weakness in 2 patients in group 1 within 5 years after diagnosis. Five patients (13%) had associated malignancies. Of 7 (19%) patients with disease onset before the age of 18 years, none had progression to myopathy. Although it presents with cutaneous lesions indistinguishable from those of classic dermatomyositis, amyopathic dermatomyositis is a distinct entity. In most patients, amyopathic dermatomyositis does not progress to myopathy. Prognosis appears favorable, but malignancy may develop.

Dermatomyositis

Dermatomyositis is an idiopathic inflammatory myopathy with characteristic skin manifestations. Although the disorder is rare, with a prevalence of one to 10 cases per million in adults and one to 3.2 cases per million in children, early recognition and treatment are important ways to decrease the morbidity of systemic complications. An association with other connective tissue disorders (overlap syndrome) and malignancy make this diagnosis particularly important to primary care physicians. Patient management includes careful evaluation for underlying malignancy and liberal use of physical therapy, antihistamines, sunscreen and oral corticosteroids. Poor prognostic indicators include poorly responsive disease, delay in diagnosis and the presence of malignancy. The therapeutic goal is to maintain function and prevent or minimize sequelae.

Dermatomyositis

Dermatomyositis is a disease that has a characteristic skin eruption that may occur with or without a proximal myopathy. The disease with cutaneous features only is classified as amyopathic dermatomyositis. The origin is unknown, but autoimmune factors are believed to play an important role. Autoantibodies are found in most patients and some have myositis-specific antibodies. Systemic changes may occur and there appears to be a relationship to internal malignancy, particularly in older patients. Juvenile disease has an associated vasculopathy. Treatment includes systemic corticosteroids and other immunosuppressive agents. The cutaneous changes may be difficult to treat.

[Inflammatory myopathies]

Primary myositis (or inflammatory myopathies) comprises three main groups of diseases, based on clinical and immunohistochemical characteristics: polymyositis (PM), dermatomyositis (DM) and inclusion body myositis. Their clinical presentation and course are disparate, but a common characteristic is immune dysfunction-related inflammation of the striated muscles. Their etiologies are still not fully elucidated but associate environmental and, to a lesser degree, genetic factors. Nevertheless, considerable progress has recently been made in the understanding and management of these diseases.

Juvenile amyopathic dermatomyositis: results of a case finding descriptive survey

OBJECTIVE

To review the clinical features of juvenile amyopathic dermatomyositis (ADM) to define an appropriate approach to its diagnosis and management.

METHODS

Based on a review of published adult and pediatric cases, a prevalidated, peer reviewed, 3 page questionnaire was sent to all members of the Pediatric Section of the American College of Rheumatology and American Society for Pediatric Dermatology.

RESULTS

Thirty-nine questionnaires were submitted for analysis. Twelve cases were excluded due to abnormal test results. Only one case met all criteria. Although 26 cases were incompletely investigated or had inadequate followup, they were not excluded, as all completed tests were normal. Two patients with incomplete data developed calcinosis. Of 27 patients not positively excluded, 10 were treated systemically, with 5 achieving remission, while 11/17 untreated recovered spontaneously. At a mean followup of 32.8 months from disease onset none of the 27 patients has developed clinical myopathy.

CONCLUSION

The classic skin changes of juvenile DM can occur in the absence of clinical muscle involvement. Physicians are not routinely performing electromyography, muscle biopsy, or magnetic resonance imaging in the assessment of these patients. A significant proportion of patients with ADM will remit without systemic therapy. Optimum treatment needs to be determined through controlled trials.

Idiopathic inflammatory muscle disease: clinical aspects

Although much remains to be learned about the immune-mediated myositis syndromes, information generated from recent studies in a number of areas may assist physicians in patient management. Topics reviewed here include: data supporting the association of myositis with cancer and the appropriate evaluations for malignancy in a myositis patient; an approach to the assessment of patients with dermatomyositis sine myositis; the usefulness of the clinicopathological and serological classifications; a discussion of whether childhood and adult myositis are the same or different entities; a review of those prognostic factors to consider in the clinical management of myositis patients; current approaches and their limitations for assessing disease activity and damage. To improve our limited understanding of the myositis syndromes, national and international collaborations are needed to obtain the necessary numbers of subjects, given the rarity and heterogeneity of these disorders.

Cutaneous features of classic dermatomyositis and amyopathic dermatomyositis

This review will focus on the work that has been reported over the past year attempting to better characterize the overall clinical significance of the cutaneous manifestations of dermatomyositis (DM). It will be organized under two headings--amyopathic dermatomyositis (ADM) and classic dermatomyositis (CDM). The distinction between these two clinical phenotypes of DM is the absence of clinically-evident muscle disease in ADM; to date it has not been possible to distinguish the cutaneous manifestations of ADM and CDM. The term hypomyopathic DM is introduced to distinguish those patients with the hallmark skin changes of DM and no clinical evidence of muscle disease who are found to have subclinical evidence of myositis upon electrophysiologic, histopathologic, and/or radiologic evaluation. Recent issues that have been raised concerning the definition, classification, epidemiology, etiopathogenesis, clinical features, treatment, differential diagnosis, and prognosis of ADM and CDM are discussed. In view of the irrefutable evidence documenting the existence of ADM for 20 years or more, the term idiopathic inflammatory dermato-myopathies may be more appropriate for this group of clinical disorders than the currently used designation, idiopathic inflammatory myopathies.

Classification criteria for the idiopathic inflammatory myopathies

Inasmuch as the clinical features of the idiopathic inflammatory myopathies are not easily differentiated from those of other similar rheumatic and neurologic conditions, diagnosis is often difficult. Various classification criteria for polymyositis and dermatomyositis have been suggested by a number of investigators. The most commonly accepted and used criteria include symmetric proximal muscle weakness, serum elevations of muscle enzymes, the classic electromyographic and muscle biopsy findings of inflammatory myopathy, and the typical skin rash of dermatomyositis. Although these criteria are clinically useful, they can result in misdiagnoses and inappropriate therapies. They also result in heterogeneous patient groups being selected for clinical and laboratory studies. Furthermore, they do not include recent findings related to the myositis-specific autoantibodies and magnetic resonance imaging of muscle that have been found to be important adjuncts in assessing patients with muscle weakness or elevations of muscle enzymes. A modification to the Bohan and Peter criteria is proposed to include myositis-specific autoantibodies and magnetic resonance imaging. This proposal could initiate productive discussions and investigations of the sensitivity and specificity of new classification criteria for myositis and could ultimately enhance our treatment capabilities.

Dermatomyositis sine myositis: association with malignancy

OBJECTIVE

To describe dermatomyositis (DM) sine myositis as a distinct diagnostic subclass of DM and the association with malignancy.

METHODS

This case series includes all patients presenting to our primary and tertiary care outpatient dermatology department with DM and DM sine myositis between 1986 and 1993. Seven patients were diagnosed with classic DM and 12 with DM sine myositis. We analyzed average age of onset, duration of followup, clinical course, and incidence of associated malignancy in the patients with classic DM and DM sine myositis.

RESULTS

No statistically significant differences were found in these 2 groups on examining age at onset and frequency of associated malignancy. Malignancy was diagnosed in 4 of 12 (25%) patients with DM sine myositis followed for a total of 50.8 patient-years (average followup 51 months) and in 2 of 7 (28%) patients with classic DM followed for a total of 20.6 patient-years (average followup 35 months).

CONCLUSION

Although these patients with DM are select and few, they demonstrate that DM sine myositis may be quite similar to classic DM. It may be said that like DM, DM sine myositis may represent a paraneoplastic syndrome. DM sine myositis should be added to the currently accepted polymyositis/dermatomyositis classification system, with appropriate emphasis on the potential association with malignancy.

Inflammatory myopathies

New information regarding myositis specific autoantibodies, histopathologic analysis of muscle biopsy specimens, and immunogenetic features of the different serologic subsets of disease has greatly increased our understanding of the pathogenesis of the inflammatory myopathies. The clinical descriptions of inclusion body myositis and 'amyopathic dermatomyositis' (Euwer and Sontheimer, 1993) are examples of our expanded descriptive capabilities in the evaluation of patients with myopathy. Finally, newer techniques such as cytokine analysis and magnetic resonance imaging may help in the ongoing assessment of disease activity in patients with myositis. The combination of these recently described clinical and laboratory parameters are enough to force a reconsideration of the previously described classification and diagnostic criteria in the inflammatory myopathies.

Classification criteria for polymyositis and dermatomyositis

OBJECTIVE

The establishment of classification criteria for polymyositis (PM) and dermatomyositis (DM).

METHODS

Questionnaires inquiring about patients with DM, PM, systemic lupus erythematosus, progressive systemic sclerosis and noninflammatory neuromuscular diseases were distributed to the main medical institutes in Japan. Data were collected and analyzed by computer.

RESULTS

Among skin lesions of DM, heliotrope rash, Gottron's sign and erythema or purpura on the extensor surfaces of the extremity joints were shown to be distinguishing criteria. In both DM and PM, proximal muscle weakness, muscle grasping and spontaneous pain, nondestructive arthritis or arthralgia, elevated CK or aldolase level, presence of systemic inflammatory signs, myogenic changes on EMG, positive and anti Jo-1 antibody and pathologic findings compatible with inflammatory myositis were distinguishing criteria items.

CONCLUSION

When a patient satisfies one of 3 skin lesion items and at least 4 other items, he or she shall be classified as having DM, sensitivity 94.1%. When a patient satisfies at least 4 items other than skin lesion items, he or she shall be classified as having PM, sensitivity 98.9%. Specificity of DM and PM is 95.2%.

Juvenile dermatomyositis: serial studies of circulating autoantibodies to a 56kD nuclear protein

In this study we report that circulating antibodies recognising a 56kD protein, which is a component of large nuclear ribonuclear particles, are commonly found in children with juvenile onset dermatomyositis (JDM). These autoantibodies, as detected by Western blotting, were present in over 90% (24/26) of sera from JDM patients, which exceeds the number of patients with adult onset myositis who express this antibody (up to 85%). In addition, they were not found in healthy controls. Serial bleeds taken during the course of the disease in eleven children with JDM enabled us to follow the titre of anti-56kD autoantibodies. Sera were also tested by indirect immunofluorescence for anti-nuclear antibodies (ANA) using Hep2 cells as substrate. These studies revealed two distinct patient groups: Group 1 with anti-56kD antibody positive and ANA positive; and Group 2 with anti-56kD antibody positive and ANA negative. In Group 1 there was some correlation between disease activity and anti-56kD levels which was absent among patients in Group 2.

A new approach to the classification of idiopathic inflammatory myopathy: myositis-specific autoantibodies define useful homogeneous patient groups

The IIM are a heterogeneous group of systemic rheumatic diseases which share the common features of chronic muscle weakness and mononuclear cell infiltrates in muscle. A number of classification schemes have been proposed for them, but none takes into consideration the marked immunologic, clinical, and genetic heterogeneity of the various clinical groups. We compared the usefulness of myositis-specific autoantibodies (anti-aminoacyl-tRNA synthetases, anti-SRP, anti-Mi-2 and anti-MAS) to the standard clinical categories (polymyositis, dermatomyositis, overlap myositis, cancer-associated myositis, and inclusion body myositis) in predicting clinical signs and symptoms, HLA types, and prognosis in 212 adult IIM patients. Although patients with inclusion body myositis (n = 26) differed in having significantly more asymmetric and distal weakness, falling, and atrophy than other patients, there were few other significant differences among the other clinical groups. In contrast, autoantibody status defined distinct sets of patients and each patient had only 1 myositis-specific autoantibody. Patients with anti-amino-acyl-tRNA synthetase autoantibodies (n = 47), compared to those without these antibodies, had significantly more frequent arthritis, fever, interstitial lung disease, and "mechanic's hands"; HLA-DRw52; higher mean prednisone dose at survey, higher proportion of patients receiving cytotoxic drugs, and higher death rates. Those with anti-signal recognition particle antibodies (n = 7) had increased palpitations; myalgias; DR5, DRw52; severe, refractory disease; and higher death rates. Patients with anti-Mi-2 antibodies (n = 10) had increased "V-sign" and "shawl-sign" rashes, and cuticular overgrowth; DR7 and DRw53; and a good response to therapy. The 2 patients with anti-MAS antibodies were the only ones with alcoholic rhabdomyolysis preceding myositis; both had insulin-dependent diabetes mellitus, and both had HLA-B60, -C3, -DR4, and -DRw53. These findings suggest that myositis-specific autoantibody status is a more useful guide than clinical group in assessing patients with myositis, and that specific associations of immunogenetics, immune responses, and clinical manifestations occur in IIM. Thus the myositis-specific autoantibodies aid in interpreting the diverse symptoms and signs of myositis patients and in predicting their clinical course and prognosis. We propose, therefore, that an adjunct classification of the IIM, based on the myositis-specific autoantibody status, be incorporated into future studies of their epidemiology, etiology, and therapy.

[Vasculitis associated with connectivitis]

A great number of vasculitis in childhood is associated with Rheumatic disease. Vascular lesions involve small vessels of various organs. These are described in systemic lupus erythematosus, juvenile rheumatoid arthritis, dermatomyositis, scleroderma, mixed connective tissue disease, Behçet syndrome, Sjögren syndrome.

[Sclerodermatomyositis. Apropos of 13 cases]

13 cases of sclero (dermato)myositis are reported with cutaneous signs specific of dermatomyositis in 6 cases. Scleroderma was rather benign, without any visceral involvement. In contrast, myositis was much more severe that usually encountered in systemic sclerosis, threatening the vital prognosis and requiring aggressive therapeutic measures to be controlled. In 6 cases, the axial musculature was involved. Occurrence of each component was not simultaneous. No case was paraneoplastic. Antinuclear antibodies were present in all cases. Antibodies against soluble nuclear antigens, specifically found by others in sclerodermatomyositis, were absent. The very peculiar clinical spectrum of this syndrome associated with immunologic abnormalities, elsewhere described, confirm the individualization of sclerodermatomyositis.

Dermatomyositis

Dermatomyositis and polymyositis are related disorders of unknown cause in which immunologic changes may be important. They sometimes overlap with other collagen vascular diseases, and not infrequently are associated with malignancy. The clinical features of the adult and juvenile forms of the disorder and the visceral manifestations of DM-PM are outlined, along with enzymatic, electromyographic, and histologic aids to diagnosis. While the cutaneous lesions often are resistant to treatment, systemic involvement may respond to corticosteroids or to immunosuppressive drugs. Treatment definitely alters the prognosis in cases not associated with malignancy.

Late recurrence of childhood dermatomyositis

Patients with childhood dermatomyositis are generally categorized into one of 3 groups: limited or monocyclic, polycyclic, or continuous. Disease resolution in those with monocyclic disease after a period of 1 to 2 years is expected and those patients are not considered at life-long risk for connective tissue disease. We describe a patient, with an uncomplicated initial course, who had disease recurrence after 8 years of disease inactivity and almost 4 years after discontinuation of all medication.