Kissed by MDA-5: lobular panniculitis of the cheek as an initial symptom of dermatomyositis

An autopsy case of anti-MDA5 antibody-positive amyopathic dermatomyositis with an initial manifestation of panniculitis on the left upper arm

A 53-year-old man was presented with refractory panniculitis on the left upper arm that had persisted for 10 months. The patient was diagnosed with lupus profundus, wherein oral glucocorticoid therapy was initiated. Four months prior, ulceration was observed in the same area. Dapson was administered instead, scarring the ulcer but enlarging the panniculitis. Five weeks earlier, he developed a fever, productive cough, and dyspnoea. Three weeks earlier, a skin rash was observed on the forehead, left auricle posterior to the neck, and extensor aspect of the left elbow. Chest computed tomography showed pneumonia in the right lung, after which the patient's dyspnoea worsened. The patient was admitted and diagnosed with anti-MDA5 antibody-positive amyopathic dermatomyositis (ADM) based on skin findings, hyperferritinaemia, and rapidly progressive diffuse lung shadows. Glucocorticoid pulse therapy, intravenous cyclophosphamide, and tacrolimus were initiated, and later, plasma exchange therapy was combined. However, his condition worsened and required management with extracorporeal membrane oxygenation. The patient expired on day 28 after hospitalisation. An autopsy revealed hyalinising to fibrotic stages of diffuse alveolar damage. Strong expression of myxovirus resistance protein A was observed in three skin biopsy specimens from the time of initial onset, consistent with ADM. Anti-MDA5 antibody-positive ADM not only manifests typical cutaneous symptoms, but also rarely occurs with localised panniculitis, such as in the present case. In patients with panniculitis of unknown aetiology, the possibility of initial symptoms of ADM should be included in the differential diagnosis.

Subcutaneous tissue involvement in idiopathic inflammatory myopathies: Systematic literature review including three new cases and hypothetical mechanisms

INTRODUCTION

Involvement of subcutaneous tissue in idiopathic inflammatory myopathies (IIM) is poorly known.

METHODS

We conducted a systematic review of the literature regarding panniculitis and lipodystrophy/lipoatrophy in juvenile and adult IIM via PubMed/Medline, Embase and Scopus databases. Three local observations are included in this review. Epidemiological, clinical, paraclinical and therapeutic data were collected.

RESULTS

Panniculitis appears to be more common in adults than in juveniles. It was mainly localised in the upper and lower limbs. Panniculitis improved in most cases with steroids and panniculitis and myositis had a similar course in 83.3% and 72.2% of cases in juveniles and adults, respectively. Lipodystrophy appeared to be more frequent in juveniles and was only observed in dermatomyositis in both juveniles and adults. Lipodystrophy was mainly partial in juveniles and adults. The median time from myositis to the diagnosis of lipodystrophy was 6 years [0-35] and 2.5 years [0-10] in juveniles and adults, respectively. Lipodystrophy was associated with anti-TIF1 gamma auto-antibody positivity, a polycyclic/chronic course of myositis and the occurrence of calcinosis and might be an indicator of poor disease control.

CONCLUSION

Adipose tissue involvement, particularly lipodystrophy, occurs almost exclusively in dermatomyositis. The insidious onset and lack of awareness of the diagnosis may underestimate its prevalence. Larger studies are needed to identify possible risk factors in these patients, to better potential underlying pathophysiological process, in order to discuss potential therapeutic targets.

Painless Panniculitis upon the Treatment of Clinically Amyopathic Dermatomyositis with Anti-MDA5 Antibody

Panniculitis, a rare cutaneous manifestation in patients with dermatomyositis (DM), usually presents as a painful erythematous lesion. We herein report a 32-year-old woman with panniculitis that appeared as an indurated plaque without pain or redness after a 4-month episode of clinically amyopathic DM during treatment with prednisolone and tacrolimus. She experienced no pain; however, the firmness and extent gradually worsened. Based on our findings, including the histopathological results, DM panniculitis was diagnosed. Azathioprine was additionally administered, leading to remission. DM panniculitis can develop as a painless induration during immunosuppressive treatment, and azathioprine may be a useful treatment.