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Anti-MDA5 Antibody-Positive Interstitial Pneumonia with Autoimmune Features Presenting as Amyopathic Hypodermatitic
Maria L Mihailescu1, Cuoghi Edens1,2, Mark D Hoffman1,3
1University of Chicago, Pritzker School of Medicine, Chicago, Illinois, USA.
Abstract:
Dermatomyositis (DM) and its variant, clinically amyopathic DM, are widely recognized entities. DM sine dermatitis, a variant without skin involvement, is less widely reported. DM with neither muscle nor skin manifestations has not been reported. We herein describe the first account of a patient with a myositis-specific antibody presenting with an array of clinical findings in the absence of both muscle and pathognomonic skin disease. This case report details the multidisciplinary assessment of an anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive individual with inflammatory polyarthropathy, mucocutaneous capillary changes, and evidence of interstitial lung disease but lacking overt skin and muscle disease. This presentation is paradoxically but appositely deemed to represent a unique form of DM, which may be best described as "amyopathic hypodermatitic dermatomyositis." Early recognition and documentation of these cases will help to characterize this variant in the future, determine its frequency, and guide management.
Insights
A rare form of dermatomyositis (DM) without skin or muscle symptoms is described. This case highlights a unique presentation of DM with specific antibodies, aiding future characterization and management.
Area of Science:
- Rheumatology
- Immunology
- Pulmonology
Background:
- Dermatomyositis (DM) is an idiopathic inflammatory myopathy.
- While DM sine dermatitis (without skin) is known, DM with neither muscle nor skin disease is unreported.
- Myositis-specific antibodies (MSAs) are crucial in diagnosing and classifying idiopathic inflammatory myopathies.
Observation:
- A case report details a patient positive for anti-melanoma differentiation-associated gene 5 (MDA5) antibody.
- The patient presented with inflammatory polyarthropathy and mucocutaneous capillary changes.
- Interstitial lung disease was evident, but overt skin and muscle disease were absent.
Findings:
- This presentation represents the first reported case of DM with neither muscle nor skin manifestations.
- The unique phenotype is termed "amyopathic hypodermatitic dermatomyositis."
- The presence of MDA5 antibody correlated with a distinct clinical profile.
Implications:
- Early identification of this DM variant is crucial for accurate diagnosis and prognosis.
- Further research is needed to determine the frequency and characteristics of this presentation.
- Recognizing this variant will aid in developing targeted management strategies for affected individuals.
