Developing classification criteria for skin-predominant dermatomyositis: the Delphi process.

BACKGROUND: The European League Against Rheumatism/American College of Rheumatology classification criteria for inflammatory myopathies are able to classify patients with skin-predominant dermatomyositis (DM). However, approximately 25% of patients with skin-predominant DM do not meet two of the three hallmark skin signs and fail to meet the criteria. OBJECTIVES: To develop a set of skin-focused classification criteria that will distinguish cutaneous DM from mimickers and allow a more inclusive definition of skin-predominant disease. METHODS: An extensive literature review was done to generate items for the Delphi process. Items were grouped into categories of distribution, morphology, symptoms, antibodies, histology and contextual factors. Using REDCap™, participants rated these items in terms of appropriateness and distinguishing ability from mimickers. The relevance score ranged from 1 to 100, and the median score determined a rank-ordered list. A prespecified median score cut-off was decided by the steering committee and the participants. There was a pre-Delphi and two rounds of actual Delphi. RESULTS: There were 50 participating dermatologists and rheumatologists from North America, South America, Europe and Asia. After a cut-off score of 70 during the first round, 37 of the initial 54 items were retained and carried over to the next round. The cut-off was raised to 80 during round two and a list of 25 items was generated. CONCLUSIONS: This project is a key step in the development of prospectively validated classification criteria that will create a more inclusive population of patients with DM for clinical research. What's already known about this topic? Proper classification of patients with skin-predominant dermatomyositis (DM) is indispensable in the appropriate conduct of clinical/translational research in the field. The only validated European League Against Rheumatism/American College of Rheumatology criteria for idiopathic inflammatory myopathies are able to classify skin-predominant DM. However, a quarter of amyopathic patients still fail the criteria and does not meet the disease classification. What does this study add? A list of 25 potential criteria divided into categories of distribution, morphology, symptomatology, pathology and contextual factors has been generated after several rounds of consensus exercise among experts in the field of DM. This Delphi project is a prerequisite to the development of a validated classification criteria set for skin-predominant DM.

Fatigue in systemic lupus erythematosus and other autoimmune skin diseases.

BACKGROUND: Fatigue is a well-established symptom in systemic lupus erythematosus (SLE), but has not been well characterized in other skin-limited autoimmune diseases such as cutaneous lupus erythematosus (CLE), amyopathic dermatomyositis (ADM) or autoimmune blistering diseases (AIBD). OBJECTIVES: In this retrospective study, we compared fatigue in controls (n = 84) with that in patients enrolled in prospective longitudinal databases with SLE (n = 165), CLE (n = 226), ADM (n = 136) and AIBD (n = 79). METHODS: We used the 36-Item Short Form Survey (SF-36) vitality scale to analyse median scores and the percentages of patients with clinically significant fatigue (defined as a score ≤ 35) between experimental groups and controls. RESULTS: Median and interquartile range (IQR) vitality scores demonstrated greater fatigue in the experimental groups (SLE 35, IQR 20-55; CLE 50, IQR 30-70; ADM 50, IQR 30-65; AIBD 55, IQR 35-70) than in controls (73, IQR 65-85) (P < 0·05 for each experimental group vs. control). The SLE group had worse fatigue than all of the other groups (P < 0·05 SLE vs. each group), but there was no difference between the CLE, ADM or AIBD groups (all P > 0·05). In addition, the experimental groups had more clinically significant fatigue (score ≤ 35) (SLE 44·2%, CLE 25·2%, ADM 31·6%, AIBD 24·1%) than controls (2%) (P < 0·01 for each experimental group vs. control). The SLE group had more clinically significant fatigue than the CLE group (P < 0·01); however, there was no difference in clinically significant fatigue between SLE and either ADM (P = 0·17) or AIBD (P = 0·055). CONCLUSIONS: These findings demonstrate that patients with skin-limited autoimmune disease experience more fatigue than controls. Fatigue is an important symptom that negatively affects quality of life for patients. It should be addressed by clinicians and measured in future clinical trials.

Evaluation of the reliability and validity of the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) in paediatric cutaneous lupus among paediatric dermatologists and rheumatologists.

BACKGROUND: The Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) is a reliable outcome measure for cutaneous lupus erythematosus (CLE) in adults used in clinical trials. However, it has not been validated in children, limiting clinical trials for paediatric CLE. OBJECTIVES: This study aimed to validate the CLASI in paediatrics. METHODS: Eleven paediatric patients with CLE, six dermatologists and six rheumatologists participated. The physicians were trained to use the CLASI and Physician's Global Assessment (PGA), and individually rated all patients using both tools. Each physician reassessed two randomly selected patients. Within each physician group, the intraclass correlation coefficient (ICC) was calculated to assess the reliability of each measure. RESULTS: CLASI activity scores demonstrated excellent inter- and intrarater reliability (ICC > 0·90), while the PGA activity scores had good inter-rater reliability (ICC 0·73-0·77) among both specialties. PGA activity scores showed excellent (ICC 0·89) and good intrarater reliability (ICC 0·76) for dermatologists and rheumatologists, respectively. Limitations of this study include the small sample size of patients and potential recall bias during the physician rerating session. CONCLUSIONS: CLASI activity measurement showed excellent inter- and intrarater reliability in paediatric CLE and superiority over the PGA. These results demonstrate that the CLASI is a reliable and valid outcome instrument for paediatric CLE.

The diagnosis and classification of amyopathic dermatomyositis: a historical review and assessment of existing criteria.

BACKGROUND: Diagnostic criteria are used to identify a patient having a disease in a clinical setting, whereas classification criteria create a well-defined population for research purposes. The diagnosis and classification of amyopathic dermatomyositis (ADM) have not been recognized by most existing criteria for idiopathic inflammatory myopathies (IIMs). To address this, several criteria were proposed to define ADM either as a distinct disease entity or as a subset of the spectrum of IIMs. OBJECTIVES: To discuss the diagnosis and classification of ADM and to assesses the available criteria in identifying cases of ADM and/or distinguishing it from dermatological mimickers such as lupus erythematosus. METHODS: We conducted an extensive literature search using the PubMed database from June 2016 to August 2018, using the search terms 'amyopathic dermatomyositis', 'diagnosis' and 'classification'. RESULTS: The European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria, which are the only validated classification criteria for adult and juvenile IIM and their major subgroups, include three cutaneous items (Göttron sign, Göttron papules, heliotrope rash) to be able to classify ADM. This international and multispecialty effort is a huge step forward in the classification of skin-predominant disease in dermatomyositis. However, about 25% of the population with ADM do not meet two out of the three skin features and are misdiagnosed or classified as having a different disease entity, most commonly lupus erythematosus. CONCLUSIONS: These gaps rationalize the continuous assessment and improvement of existing criteria and/or the development of validated, separate and skin-focused criteria for DM.