P052 Case series: a rare form of calcinosis in patients with systemic sclerosis-myositis overlap

Abstract Background/Aims Calcinosis is a well described entity that occurs in systemic sclerosis (SSc) and dermatomyositis. In patients with SSc, calcinosis typically occurs over pressure points but very rarely, widespread calcinosis may occur, presenting in an extensive pattern. We present a case series of four patients with SSc with this rarer form of diffuse calcinosis with the aim of raising awareness of this poorly recognised pattern of debilitating disease. Methods Four cases of SSc with extensive calcinosis were identified from a cohort of 461 patients with SSc who had attended a tertiary referral centre over the preceding 3 years, and their case notes reviewed. Results Demographic and clinical features of the four patients are summarised in Table 1. All four patients had the diffuse cutaneous subtype of SSc in the context of 102 patients [22%] of the entire SSc cohort of 461 patients, and all had overlapping features of myositis. Two were anti-Scl 70 antibody positive and the other two were anti-PMScl- positive. Widespread calcinosis was evident in all four patients in a pattern akin to ‘sheets’ of calcified deposits, very different to the lobular pattern of disease that has been well-described in the literature. Development of calcinosis occurred between one and six years of the onset of SSc, and in one patient the calcinosis discharged through skin at multiple sites. In all patients, treatment included mycophenolate mofetil. Treatments tried for the calcinosis included intravenous sodium thiosulfate in two patients (on the basis of anecdotal reports), but without significant clinical improvement. P052 Table 1: Demographic and clinical features. Characteristic Case 1 Case 2 Case 3 Case 4 Current age (years) 68 70 51 33 Age at diagnosis of systemic sclerosis (years) 65 65 42 27 Sex Male Female Female Female Estimated disease duration prior to onset of calcinosis 1 year 3 years 6 years 2 years Auto-antibody profile Anti- Scl70 +ve Anti-PMScl-75 weakly +ve, Anti- PMScl-100 weakly +ve Anti-PMScl +ve Anti- Scl70 +ve, dsDNA +ve Imaging features Calcinosis around the pelvis, upper femora, elbows, first web space of the hands (bilateral), distal rib cage Calcinosis around the forearms, elbows, thighs and hands Calcinosis around the pelvis Calcinosis of upper arms, thighs, legs and left wrist Previous or current treatments Mycophenolate mofetil 1g BD, Prednisolone (maximum dose 20mg daily), Minocycline 50mg daily Mycophenolate mofetil 1g BD, Prednisolone (