also had depression. She had her menopause at 52, was on calcium and vitamin D supplements. She was athletic, never smoked and took two units of alcohol a week. Her mother had a hip fracture. She presented to her GP with severe low back pain, not responding to NSAIDs. Initial X-ray did not show any fractures. However, her low back pain worsened while trying to lift heavy weight, this time more localised on the left. MRI scan showed high signal changes in the left sacral ala. She then had a CT scan of pelvis which showed marked phenolate mofetil (MMF). Methods: A 55-year-old Caucasian labourer was admitted with five weeks of worsening limb weakness, swallowing difficulties, inability to walk and 1.5 stone weight loss. Two weeks earlier, he had attended hospital with similar symptoms that were attributed to steroid-induced myopathy from oral budesonide taken for new microscopic colitis. Stopping budesonide made no improvement to his symptoms. He had background of hypertension but no statin use. On examination, he had mild quadriceps wasting with proximal muscle weakness (hip flexion MRC 2/5). No rashes, stigmata of connective tissue disease or other signs on systems review. Urinalysis was 2þ positive for blood. CK was elevated at 8712 U/L with CRP 6.6 mg/L and ESR 24 mm/hr. ANA was negative (<1/100, cytoplasmic staining was observed), myositis antibody panel was requested. MRI upper and lower limbs revealed features in keeping of polymyositis more pronounced in the thighs. EMG revealed myopathic pattern with inflammatory features (fibrilla- tions). CT chest-abdomen-pelvis showed no malignancy but suspicion of interstitial lung disease (ILD). Serial pulmonary function testing was stable with all parameters >70% predicted. Results: Pulsed intravenous methylprednisolone was followed by prednisolone 50mg daily. MMF was chosen over methotrexate for maintenance in view of ILD. CK fell to 3469 U/L post-methylpredniso- lone then remained stagnant for 2 further weeks. His muscle strength showed little improvement over this period. A muscle biopsy was undertaken, followed by a 5-day course of IVIG. Subsequently, CK normalized within four weeks to 214 U/L and patient’s muscle strength and mobility significantly improved with intensive rehabilitation. Two months’ post-discharge he remains on 20mg prednisolone daily, MMF 1g twice daily, and is independently mobilizing with a frame. Quadriceps muscle biopsy subsequently showed features of an immune-mediated necrotizing myopathy. Myositis antibodies came back positive for anti-SRP but negative for anti-HMG-CoA reductase. Conclusion: The outcome of anti-SRP myopathy is poor with only half of patients recovering normal strength after 4 years. First line treatment remains corticosteroid with differing maintenance DMARD choices often methotrexate. Here, we show in light of ILD, MMF to be an adequate choice and give support to the idea that IVIG be used early on given its excellent response here. We remind clinicians to be confronted with an apparent steroid-resistant Borukhson: None. P. Yee: None. K. Baburaj: PRESENTATION OF POLYARTERITIS Plastiras 1 and Joanne Ledingham 1 Alexandra Hospital, Portsmouth, UNITED nodosa (PAN) is an ANCA-negative, with an estimated prevalence up to 30 per most cases present with multi-systemic features in presenting with isolated muscular involvement. the case of a 47 year old male who attended the with 7 days of progressive bilateral lower limb he was struggling to walk due to pain, worst in temperature 38.6c, tachycardia 115bpm, sweat- 21.3, CK normal. He had no previous medical consuming less than 14 units alcohol/ a marine engineer, latest travel being to Bahrain 5 a viral screen and throat swab were negative fever, inflammatory syndrome and myalgia Lower limb ultrasound was requested due to this showed myositis/fasciitis/panniculitis, o rheumatology. History and examination yielded ther organ involvement. During admission he lost anaemia: Hb 106 (149 on admission) and ALP 382, ALT 236, with an unremarkable Further investigations included negative urina- ANA, ANCA and cardiolipin; normal bone CTCAP. CTPET with F18-fluorodeox- vascular-related activity in all limbs. MRI but showed fascial oedema and wide- in the thighs and calves, suggestive of fasciitis. biopsies demonstrated angiocentric infiltration of size arteries with no leukocytoclasis, eosino- or granulomas. It was decided to commence IV for a medium vessel vasculitis, consistent with the of Rheumatology Criteria for PAN. Prior to he developed bilateral leg non-blanching palpable purpura, a possible cutaneous vasculitis. He proceeded to receive methylprednisolone and reported improvement within hours. He was discharged on oral steroids and will be considered for steroid- sparing agents in due course. Conclusion: Inflammatory syndrome has multiple non-infectious causes which must be considered, especially if refractory to antimicrobials. While myalgia is a common presentation of PAN, the absence of systemic symptoms, particularly alongside normal CK and autoimmune screen, may be dissuasive for a medical team consider- ing differentials. Literature review reveals increasing reports of isolated lower limb muscular PAN. It is unclear whether these represent a sub- type of disease or an initial symptom where commencing treatment masks development of extra-muscular symptoms. MRI consistently demonstrates hyper-intensity on T2/STIR sequences, and subsequent biopsy is crucial for diagnosis and guiding investigation and manage- ment. In this instance steroid therapy was commenced within 3 weeks of presentation and 4 weeks of symptom onset, resulting in rapid symptom resolution and enabling discharge from hospital. Disclosures: E.C. Rose: None. A. Plastiras: None. J. Ledingham: None. E038 A CHALLENGING CASE OF SEVERE ULCERATIVE PROCTITIS AND FATIGUE FOLLOWING SIX MONTHS’ TREATMENT WITH SECUKINUMAB IN A PATIENT WITH PSORIATIC ARTHRITIS Alice Cotton 1 , Coziana Ciurtin 1 and Alexis Jones 1 1 Rheumatology, University College London, London, UNITED KINGDOM iii174 Thursday 2 May 2019 INVITED SPEAKERS ABSTRACTS Downloaded from https://academic.oup.com/rheumatology/article/58/Supplement_3/kez110.037/5444774 by guest on 11 March 2023