From the Guidelines
Calcific Dermatomyositis Overview
Calcific dermatomyositis, also known as juvenile dermatomyositis with calcinosis, is a rare and severe subtype of dermatomyositis characterized by the deposition of calcium in the skin and muscles, often associated with a delay in diagnosis and treatment 1.
Key Characteristics and Treatment Goals
The primary treatment goal is to control inflammation, prevent further calcification, and manage symptoms. According to recent consensus-based recommendations for the management of juvenile dermatomyositis, treatment should aim at controlling disease activity, preventing organ damage, and improving quality of life 1.
Recommended Treatment Approaches
Recommended initial treatment includes:
- High-dose corticosteroids, such as prednisone, for at least 3-6 months to control inflammation.
- Methotrexate or azathioprine as steroid-sparing agents to reduce the side effects of long-term corticosteroid use.
- Hydroxychloroquine for its anti-inflammatory and immunomodulatory effects.
- Topical treatments for skin lesions.
Additionally, measures to prevent further calcification include:
- Maintaining adequate hydration and urine output.
- Avoiding excessive calcium and vitamin D intake.
- Considering bisphosphonates in cases with significant calcification, although their effectiveness is still under investigation 1.
Monitoring and Adjusting Treatment
Close monitoring of disease activity, muscle strength, and calcium levels is essential to adjust treatment as needed. In severe cases, intravenous immunoglobulin (IVIG) or other immunosuppressive agents may be considered. The treatment of calcinosis itself is challenging, with several agents having been used with minimal or no improvement, although diltiazem may produce a partial response 1.
Importance of Specialized Care
Given the rarity and severity of calcific dermatomyositis, it is crucial that patients are cared for in centers with experience and expertise in this condition to ensure optimal management and support 1.
From the Research
Definition and Prevalence of Calcific Dermatomyositis
Calcific dermatomyositis, also known as juvenile dermatomyositis with calcinosis, is a condition characterized by the deposition of insoluble calcium salts in the soft tissues, including skin, subcutaneous tissue, tendons, fascia, and muscle 2, 3. This condition is a complication of dermatomyositis, an immune-mediated myopathy that affects approximately 8% of patients with dermatomyositis 4. The prevalence of calcinosis is higher in juvenile dermatomyositis, affecting up to 75% of patients, compared to adult dermatomyositis, which affects up to 20% of patients 3.
Pathogenesis and Risk Factors
The exact mechanism of calcinosis remains unclear, but several pathogenic hypotheses have been proposed, including:
- Intracellular accumulation of calcium secondary to an alteration of the cellular membrane by trauma and inflammation 2
- Local vascular ischemia 2
- Dysregulation of mechanisms controlling the deposition and solubility of calcium and phosphate 2
- Mitochondrial damage of muscle cells 2, 5
- Neutrophil activation and mitochondrial dysfunction have recently emerged as potential mechanistic pathways involved in calcinosis pathogenesis 3
Clinical Features and Treatment
Calcinosis can lead to significant patient morbidity, with symptoms including inflammation, ulceration, pain, and local and systemic infections 4. Treatment options are limited, and surgical excision is often the mainstay of treatment 3, 5. Other treatment options include:
- Topical and intralesional sodium thiosulfate 3, 5
- JAK inhibitors, which appear to be a promising therapy in juvenile dermatomyositis 3
- Minocycline, which can be useful for lesions associated with surrounding inflammation 5
- Vasodilators, such as prostacyclin analogs, which may have promise in the treatment of calcinosis, but further studies are necessary 5