Juvenile-onset clinically amyopathic dermatomyositis: an overview of recent progress in diagnosis and management

Undercover lung damage in pediatrics - a hot spot in morbidity caused by collagenoses

Connective tissue represents the support matrix and the connection between tissues and organs. In its composition, collagen, the major structural protein, is the main component of the skin, bones, tendons and ligaments. Especially at the pediatric age, its damage in the context of pathologies such as systemic lupus erythematosus, scleroderma or dermatomyositis can have a significant negative impact on the development and optimal functioning of the body. The consequences can extend to various structures (e.g., joints, skin, eyes, lungs, heart, kidneys). Of these, we retain and reveal later in our manuscript, mainly the respiratory involvement. Manifested in various forms that can damage the chest wall, pleura, interstitium or vascularization, lung damage in pediatric systemic inflammatory diseases is underdeveloped in the literature compared to that described in adults. Under the threat of severe evolution, sometimes rapidly progressive and leading to death, it is necessary to increase the popularization of information aimed at physiopathological triggering and maintenance mechanisms, diagnostic means, and therapeutic directions among medical specialists. In addition, we emphasize the need for interdisciplinary collaboration, especially between pediatricians, rheumatologists, infectious disease specialists, pulmonologists, and immunologists. Through our narrative review we aimed to bring up to date, in a concise and easy to assimilate, general principles regarding the pulmonary impact of collagenoses using the most recent articles published in international libraries, duplicated by previous articles, of reference for the targeted pathologies.

Juvenile idiopathic inflammatory myositis: an update on pathophysiology and clinical care

The childhood-onset or juvenile idiopathic inflammatory myopathies (JIIMs) are a heterogenous group of rare and serious autoimmune diseases of children and young people that predominantly affect the muscles and skin but can also involve other organs, including the lungs, gut, joints, heart and central nervous system. Different myositis-specific autoantibodies have been identified that are associated with different muscle biopsy features, as well as with different clinical characteristics, prognoses and treatment responses. Thus, myositis-specific autoantibodies can be used to subset JIIMs into sub-phenotypes; some of these sub-phenotypes parallel disease seen in adults, whereas others are distinct from adult-onset idiopathic inflammatory myopathies. Although treatments and management have much improved over the past decade, evidence is still lacking for many of the current treatments and few validated prognostic biomarkers are available with which to predict response to treatment, comorbidities (such as calcinosis) or outcome. Emerging data on the pathogenesis of the JIIMs are leading to proposals for new trials and tools for monitoring disease.

Juvenile Idiopathic Inflammatory Myopathies

The juvenile idiopathic inflammatory myopathies (JIIM) are a group of rare, chronic, autoimmune illnesses that affect muscle and, to a lesser extent, skin. The presence of new-onset weakness and, in juvenile dermatomyositis, typical rahes, should lead to consideration of these diagnoses. Careful evaluation to exclude alternative diagnoses is needed. Investigations include a variety of blood tests, imaging, and possibly muscle biopsy. Validated clinical assessments are available for monitoring. Standard treatment includes corticosteroids and methotrexate and often extends beyond 1 year. Outcomes are generally good, but disease persistence remains problematic. Early involvement of providers with expertise in JIIM is essential.

MDA5 autoantibody-another indicator of clinical diversity in dermatomyositis

Allenbach and colleagues have recently reported for the first time the results of an intriguing study of the histopathologic, immunopathologic and gene expression differences in muscle biopsy tissue from adult dermatomyositis (DM) patients who do and do not have circulating MDA5 autoantibodies (anti-MDA5). Anti-MDA5 were originally identified in a clinically-defined subset of DM patients whose disease was expressed predominately in the skin for unusually long periods of time without accompanying muscle weakness [i.e., "clinically-amyopathic DM" (CADM)] and were at risk for acute, rapidly-progressive form of interstitial lung disease (ILD). As an academic dermatologist in the United States of America (USA) having a career-long interest in the CADM subset, I would like to share my perspective on the results of the work by Allenbach and colleagues and offer some suggestions for additional study in this area. But to do so most effectively, I first would like to review the clinical concept of CADM and its association with anti-MDA5 antibody production and a potentially-fatal form of (ILD).

Inflammatory Myopathies with Cutaneous Involvement: from Diagnosis to Therapy

The group of idiopathic inflammatory myopathies (IIM) include various disorders of skeletal muscles with or without skin involvement. The most common types are dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) and necrotizing autoimmune myopathy (NAM). Dermatomyositis subdivides into various clinical forms such as juvenile, amyopathic or paraneoplastic dermatomyositis, scleromyositis, overlap or anti-synthetase syndromes, etc.

Recently, numerous new antibodies defining the characteristic clinical phenotype have been described as anti-MDA5 antibodies associated with interstitial lung disease and amyopathic dermatomyositis or anti-TIF1γ antibodies as markers for paraneoplastic dermatomyositis. Moreover, new clinical entities as drug-induced dermatomyositis are presumed, since some medications may induce, or trigger inflammatory myopathies.

Knowledge of the complex methods and techniques required to diagnose the disease is of great importance in clinical practice. The variety of clinical variants needs diagnosis because of the differing prognosis and therapeutic modalities.

Childhood Arthritis and Rheumatology Research Alliance consensus clinical treatment plans for juvenile dermatomyositis with skin predominant disease

BACKGROUND

Juvenile dermatomyositis (JDM) is the most common form of the idiopathic inflammatory myopathies in children. A subset of children have the rash of JDM without significant weakness, and the optimal treatments for these children are unknown. The goal of this study was to describe the development of consensus clinical treatment plans (CTPs) for children with JDM who have active skin rashes, without significant muscle involvement, referred to as skin predominant JDM in this manuscript.

METHODS

The Children's Arthritis and Rheumatology Research Alliance (CARRA) is a North American consortium of pediatric rheumatology health care providers. CARRA members collaborated to determine consensus on typical treatments for JDM patients with skin findings without significant weakness, to develop CTPs for this subgroup of patients. We used a combination of Delphi surveys and nominal group consensus meetings to develop these CTPs.

RESULTS

Consensus was reached on patient characteristics and outcome assessment, and CTPs were developed and finalized for patients with skin predominant JDM. Treatment option A included hydroxychloroquine alone, Treatment option B included hydroxychloroquine and methotrexate, and Treatment option C included hydroxychloroquine, methotrexate and corticosteroids.

CONCLUSIONS

Three CTPs were developed for use in children with skin predominant JDM, which reflect typical treatment approaches. These are not considered to be specific recommendations or standard of care. Using the CARRA network and prospective data collection, we will be able to apply statistical methods in the future to allow comparisons of JDM patients following these consensus treatment plans.

Tumoral Calcinosis as an Initial Complaint of Juvenile-Onset Amyopathic Dermatomyositis

Calcinosis is rarely observed in juvenile-onset amyopathic dermatomyositis in contrast to juvenile-onset dermatomyositis. A 6-year-old female presented with several 0.5 to 2 cm-sized painless grouped masses on both knees for 3 years. The patient also presented with multiple erythematous scaly patches and plaques on both elbows, knuckles, buttock, ankles and cheeks. Her mother had similar skin lesions which were erythematous scaly patches on the knuckles and elbows, since her childhood. When skin biopsy was performed from a left knee nodule, liquid chalky discharge was observed. The biopsy results were consistent with calcinosis cutis. Other biopsies from erythematous patch of the patient and erythematous patch of her mother showed vacuolization of basal cell layer with inflammatory cell infiltrations. Laboratory findings showed normal range of serum phosphorus (4.5 mg/dl), calcium (9.3 mg/dl), 1,25-dihydroxy-vitamin D (10.8 ng/ml) and parathyroid hormone levels (11 pg/ml). Both patient and her mother had no history of muscle weakness and showed normal levels of muscle-specific enzyme. Both patients were diagnosed with juvenile-onset amyopathic dermatomyositis based on histopathology and cutaneous manifestations with no evidence of muscle weakness and no serum muscle enzyme abnormalities. Tumoral calcium deposits observed in daughter was diagnosed as dystrophic calcinosis which can be rarely seen in juvenile-onset amyopathic dermatomyositis. The patient is being treated with oral acetazolamide (40 mg/kg/d) for calcinosis.

Review of the cutaneous manifestations of autoimmune connective tissue diseases in pediatric patients

Autoimmune connective tissue diseases are chronic inflammatory disorders associated with complex genetic and environmental interplay resulting in a variety of cutaneous and systemic manifestations. Pediatric onset of these disorders carries a unique diagnostic pressure for the clinician due to the potential years of disease burden and complications. Mortality and morbidity from these disorders has fallen dramatically over the past fifty years due to increasing awareness of these disease sequelae and utilization of systemic treatment modalities when necessary. This review highlights the clinical features that are unique to pediatric presentations of lupus erythematosus, juvenile idiopathic arthritis, juvenile dermatomyositis, juvenile onset systemic sclerosis and morphea. Each of these disorders has a distinct appearance corresponding to a particular cutaneous and systemic clinical course and prognosis. Awareness of the associated potential systemic complications can also alert the clinician to make astute management decisions when confronted with a probable rheumatologic case. Cutaneous symptoms may predate onset of systemic symptoms and by keeping the rheumatologic differential diagnoses in mind, the dermatologist can play a key role in potentially offsetting autoimmune disease burden in children.

A hyper-ferritinemia syndrome evolving in recurrent macrophage activation syndrome, as an onset of amyopathic juvenile dermatomyositis: a challenging clinical case in light of the current diagnostic criteria

Juvenile dermatomyositis is an immune-mediated inflammatory multi-system disease involving mainly striated muscles and skin. Typical dermatological features are fundamental to establish the diagnosis, especially whenever the myopathy is very mild or absent, as it occurs in the form called as amyopathic juvenile dermatomyositis. Sometimes, systemic rheumatic diseases can develop a hyperferritinemia syndrome characterized by hemophagocytosis, namely macrophage activation syndrome, which represents a severe and life-threatening complication. Here, we describe a complex clinical history characterized by a hyper-ferritinemia syndrome after infectious mononucleosis, leading to recurrent episodes of macrophage activation syndrome. Finally, the late onset of several skin changes brought to a diagnosis of amyopathic juvenile dermatomyositis.

Developments in the classification and treatment of the juvenile idiopathic inflammatory myopathies

This review updates recent trends in the classification of the juvenile idiopathic inflammatory myopathies (JIIM) and the emerging standard of treatment of the most common form of JIIM, juvenile dermatomyositis. The JIIM are rare, heterogeneous autoimmune diseases that share chronic muscle inflammation and weakness. A growing spectrum of clinicopathologic groups and serologic phenotypes defined by the presence of myositis autoantibodies are now recognized, each with differing demographics, clinical manifestations, laboratory findings, and prognoses. Although daily oral corticosteroids remain the backbone of treatment, disease-modifying anti-rheumatic drugs are almost always used adjunctively and biologic therapies may benefit patients with recalcitrant disease.

Hydroxyurea-induced dermatomyositis: true amyopathic dermatomyositis or dermatomyositis-like eruption?

BACKGROUND

  Hydroxyurea-induced dermatomyositis is a rare adverse reaction of long-term hydroxyurea therapy. It has been reported under different names; however, the exact classification and nomenclature of this eruption have been the subject of much debate, and a more precise term is still awaiting. Herein, we review the different aspects of this reaction and suggest a new term that might help to minimize the confusion about its nomenclature.

MATERIALS AND METHODS

We describe a 68-year-old woman who had been on long-term hydroxyurea therapy for the treatment of chronic myeloid leukemia for nine years. She presented with typical dermatomyositis-like lesions and many of the other mucocutaneous adverse effects of hydroxyurea.

RESULTS

Skin examination revealed typical Gottron's papules on the dorsa of the hands, atrophy, xerosis, acquired ichthyosis, photosensitivity, cutaneous, oral and nail hyperpigmentation, acral erythema, palmoplantar keratoderma, actinic keratoses, and leg ulcers. There was no clinical or laboratory evidence of proximal muscle weakness. Cessation of hydroxyurea was associated with remarkable improvement of the skin lesions.

CONCLUSION

Hydroxyurea-induced dermatomyositis is a rare drug-induced dermatomyositis characterized by skin lesions identical to classic dermatomyositis without clinical or laboratory evidence of myositis. We propose that the term hydroxyurea-induced amyopathic dermatomyositis that adequately describes the findings reported in this subset of patients would be more precise and specific.

Update on the management of chronic eczema: new approaches and emerging treatment options

Atopic dermatitis (AD) is a common disease with worldwide prevalence, affecting up to 20% of children and 3% of adults. Recent evidence regarding pathogenesis has implicated epidermal barrier defects deriving from filagrin mutations with resulting secondary inflammation. In this report, the authors comprehensively review the literature on atopic dermatitis therapy, including topical and systemic options. Most cases of AD will benefit from emollients to enhance the barrier function of skin. Topical corticosteroids are first-line therapy for most cases of AD. Topical calcineurin inhibitors (tacrolimus ointment, pimecrolimus cream) are considered second line therapy. Several novel barrier-enhancing prescription creams are also available. Moderate to severe cases inadequately controlled with topical therapy may require phototherapy or systemic therapy. The most commonly employed phototherapy modalites are narrow-band UVB, broadband UVB, and UVA1. Traditional systemic therapies include short-term corticosteroids, cyclosporine (considered to be the gold standard), methotrexate, azathioprine, mycophenolate mofetil, and most recently leflunamide. Biologic therapies include recombinant monoclonal antibodies acting on the immunoglobulin E / interleukin-5 pathway (omalizumab, mepolizumab), acting as tumor necrosis factor-α inhibitors (infliximab, etanercept, adalimumab), and acting as T-cell (alefacept) and B-cell (rituxumab) inhibitors, as well as interferon γ and intravenous immunoglobulin. Efficacy, safety, and tolerability are reviewed for each medication.