TBA (17A149)

An unusal presentation of primary myositis with lung involvement mimics compartment syndrome: Is it a medical emergency?

Author(s)

Alwin Sebastian, Maria Usman Khan, Fahd Adeeb, Wan Lin Ng, Aqeel Anjum, Mary Brady, Mary Gillespie, Fiona Irwin, Siobhan Morrisey, Breda McCarthy, Joseph Devlin, Alexander Fraser, John Paul Doran

Department(s)/Institutions

Rheumatology Department, University Hospital Limerick Group

Introduction

Idiopathic inflammatory myopathies (IIM) [1,2] are a group of rare connective tissue diseases (CTD) characterised by muscular and extra muscular signs, with lung involvement being a frequent and challenging issue [3-5]

Aims/Background

We present an interesting case of primary myositis with ILD who was successfully treated with immunosuppressant

Method

A 59 years old man presented with 5 days history of bilateral calf pain (R>L) increases while walking which was initially very tender. He was extremely fatigued for last few weeks associated with progressively worsening shortness of breath on exertion, weight loss and dysphagia for solids and liquids. His past medical history reveals bilateral partial nephrectomy secondary to renal cell carcinoma, excision of a basal cell carcinoma lesion from the right temporal area, Raynauds syndrome, ILD, hx of shingles and hypertension. On examination he has mild right calf tenderness and has no muscle weakness nor focal neurological deficit. Auscultation of the lungs heard bibasal inspiratory crepitation. He has very high muscle and cardiac enzymes and elevated inflammatory markers (CK-13000, TT-1100). Initial investigations of ECG, telemetry, Doppler US of lower limbs, cardiac echo, and ANA were normal. Secondary investigations of myositis panel, CT TAP and MRI of the calves were very abnormal with normal cardiac MRI and trans-bronchial biopsy.

Results

He had a positive anti EJ antibody and weakly positive anti PL-12 antibody. CT TAP showed mediastinal lymphadenopathy and MRI of left calf showed posterior compartment diffuse swelling and oedema (image-1) misleads towards compartment syndrome

He was treated as primary myositis with pulsed IV methyprednisolone, Methotrextae and Rituximab. His functional ability improved and his muscle, cardiac enzymes and inflammatory markers showed a significant improvement (figure-1)

Conclusions

ILD is a leading cause of morbidity in inflammatory myopathies. New autoantibodies associated with various clinical phenotypes have facilitated the diagnosis of IIMs, and contributed to better estimates of the risk and prognosis. Treatment depends on the severity and progression of myositis and ILD at diagnosis, and includes high-dose corticosteroids, often with additional immunosuppressive drugs.