Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose: The new European League Against Rheumatism / American College of Rheumatology (EULAR / ACR) classification criteria for inflammatory myopathies are able to identify patients with dermatomyositis (DM). However, approximately 25% of patients with purely cutaneous DM do not meet 2 out of the 3 hallmark skin signs and fail to meet the criteria for myositis. To allow a more inclusive definition of cutaneous DM, we are developing a skin-focused classification criteria based on the consensus of international experts in the Rheum/Derm field. This project specifically aims to distinguish skin findings in DM from potential mimickers.
Methods: An extensive literature review was done. International experts participated in several nominal group discussions to generate items for the Delphi. Items were grouped into categories of distribution, morphology, symptoms, antibodies, histology, and contextual factors. Using REDCap, participants rated these items in terms of their appropriateness and their ability to distinguish DM from other diagnoses. The relevance score ranged from 1 to 100 and the median of each item determined the rank-ordered list. A pre-specified median score cut-off was decided by the steering committee and the participants. There were 2 rounds in this Delphi criteria project.
Results: There were 50 respondents composed of dermatologists and rheumatologists from North America, South America, Europe and Asia. After subjecting the items to a cut-off score of 70 during the first round, 37 out of the 54 items were retained and carried over to the next round. The cut-off was then raised to 80 for the second round, and a list of 22 items (Table 1) was generated for potential inclusion into a set of items that will be used to validate classification criteria in a prospective case-control study.
Conclusion: This project is a key step in the development of prospectively validated criteria that will create well-defined cohorts for clinical research on novel treatments for DM.
Table 1. Potential Cutaneous DM Classification Criteria*
Path / Lab (median)
Contextual Factors (median)
V of Neck (80) Elbow, Knee (80)
MCP IP Joints
joint macules (86)
Nailfold erythema (80)
Cuticular Dystrophy (85)
Fissuring of digits (80)
Eyelid edema (80) Palmar macules and papules (81)
Pruritus of scalp (80) Photosensitivity (80)
Interface dermatitis (90)
Dermal Mucin (80)
Presence of myositis antibodies (88.5)
disease (80) Muscle weakness (85)
*Items generated after 2 rounds of Delphi
To cite this abstract in AMA style:Concha J, Werth VP, Merola JF, Fiorentino D, Dutz J, Fujimoto M, Goodfield M, Ang CC, Nyberg F, Volc-Platzer B. Developing a Classification Criteria for Cutaneous Dermatomyositis Utilizing the Delphi Technique [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 10). https://acrabstracts.org/abstract/developing-a-classification-criteria-for-cutaneous-dermatomyositis-utilizing-the-delphi-technique/. Accessed July 11, 2020.
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