Large vessel vasculitis in a patient with a background of atypical PMR and normal inflammatory markers
Julie-Ann Henderson, Rosemary Friel, Stephen McDonald, Philip V Gardiner
Altnagelvin Area Hospital, Western Health and Social Care Trust
A 67 year old lady was admitted in 2011 and extensively investigated for generalised myalgia and weakness with systemic upset. She had failed to respond to a trial of 40mg of prednisolone prescribed by her GP for presumed PMR. ESR 49, CRP 91. ANCA, ANA and infection screen negative. PET CT 4 weeks later showed features in keeping with PMR.
Steroids were recommenced at 30mg/d and ESR returned to normal. However, the patient continued to report ongoing generalised arthralgia and myalgia in spite of a normal ESR. Methotrexate was introduced and prednisolone was not weaned until 2014. ESR since 2012 has remained within normal range.
In 2016 she developed claudication symptoms affecting all four limbs which progressed to near critical ischaemia of her right hand. CTA showed bilateral subclavian and axillary artery atheroma with some focal narrowing in both axillary arteries. USS Doppler lower limbs confirmed further stenoses. She underwent right subclavian artery angioplasty with some initial benefit. PET CT was arranged.
PET CT scans were compared:
2012: Findings included bursitis affecting shoulders, hip joints, ischial tuberosities and interspinous bursa, in-keeping with PMR.
2017: New findings included abnormal uptake in the aorta and great branches, right subclavian, axillary arteries, abdominal aorta, right common and internal iliac and left SFA, in-keeping with large vessel vasculitis. Of note, the previous bursitis had resolved.
With a new diagnosis of large vessel vasculitis, the dose of MTX dose was increased, steroids were recommenced and she has been commenced on Tocilizumab. However, it is difficult to know how best to monitor response to therapy in the setting of normal inflammatory markers and some ongoing symptoms due to established vascular stenosis. PET CT has emerged as an important diagnostic test, but its role in evaluating therapy response is not clearly established.
This case also highlights the difficulty in managing those with atypical/ongoing symptoms of PMR and normal inflammatory markers. It is not unusual for patients to have ongoing pain secondary to other causes such as rotator cuff disease, osteoarthritis and long-term steroid side effects. It may be difficult to differentiate these patients from those that may have the more unusual but potentially catastrophic diagnosis of large vessel vasculitis.
The dilemma arises of who to investigate, when and how. Is there a role for axillary artery US? Will PET/CT become a more common tool? Furthermore, choice of biologic and duration of therapy has not been established.