CPD 102: ARTERITIS Continuing Professional Development
CPD 60 Second Summary Giant cell arteritis (GCA) is the most common form of systemic vasculitis. Its incidence demonstrates a strong association with aging. GCA will affect 1 in 100 women and 1 in 200 men in Ireland in their lifetime. Characteristic symptoms include temporal headache, jaw pain, and systemic features. Devastating irreversible ischaemic complications such as vision loss and stroke may occur at disease onset. In the longer term, complications such as aortic aneurysms may occur. Inflammatory markers (ESR and CRP) are generally elevated, but not always markedly so. Temporal artery biopsy remains the gold standard for diagnosis but has poor sensitivity. The utility of temporal artery ultrasound and other imaging techniques has progressed in recent years. Glucocorticoids remain an indispensable part of the treatment algorithm but are associated with a multitude of treatment related adverse events. The biologic agent tocilizumab has emerged as a key part of GCA treatment, facilitating lower cumulative glucocorticoid doses and reducing flare rates. The majority of people with GCA should now be initiated on combination treatment in order to minimise treatment related complications and improve long term outcomes. Uncertainties remain but significant progress has been made in GCA management in recent years.
41
AUTHOR: Professor Richard Conway, Consultant Rheumatologist, St. James Hospital; Clinical Associate Professor, Trinity College Dublin Richard Conway graduated from the Royal College of Surgeons in Ireland in 2006. He completed rheumatology and general internal medicine training in Ireland in 2014, and a PhD in giant cell arteritis at University College Dublin in 2017. He is currently a consultant rheumatologist and physician at St. James’s Hospital and a clinical associate professor at Trinity College Dublin. He is the author of more than 150 peer-reviewed publications and 3 book chapters. His research interests include interstitial lung disease in systemic rheumatic diseases and systemic vasculitis.
1. REFLECT - Before reading this module, consider the following: Will this clinical area be relevant to my practice?
knowledge gap - will this article satisfy those needs - or will more reading be required?
2. IDENTIFY - If the answer is no, I may still be interested in the area but the article may not contribute towards my continuing professional development (CPD). If the answer is yes, I should identify any knowledge gaps in the clinical area.
4. EVALUATE - Did this article meet my learning needs - and how has my practise changed as a result?Have I identified further learning needs?
3. PLAN - If I have identified a
5. WHAT NEXT - At this time you may like to record your learning for future use or assessment. Follow the
4 previous steps, log and record your findings. Published by HPN. Copies can be downloaded from www.irishpharmacytraining.ie Disclaimer: All material published is copyright, no part of this can be used in any other publication without permission of the publishers and author.
Giant Cell Arteritis Introduction
Clinical Presentation
Giant cell arteritis (GCA) is a systemic inflammatory rheumatic disease. It is the commonest form of systemic vasculitis in Ireland. It has a striking age predilection, virtually never occurring prior to age 50 and becoming more common until a peak in the 70’s with a plateau thereafter. GCA demonstrates a marked geographic preponderance being strikingly more common in Northern European populations than in other parts of the world. This association seems to be genetically based rather than due to physical location with emigrant populations maintaining the risk of their ancestral origin. The lifetime risk of GCA in populations similar to Ireland is 1% in women and 0.5% in men – this is not a rare condition.1 The cause of GCA is unknown; the marked age association suggests a key role for immunosenescence. It is hypothesised that a particular individual’s immune system may be primed, by aging and/or other factors, to develop GCA, and then a subsequent second hit triggers the disease. The nature of this trigger has been elusive, and this may reflect the fact that there is no specific trigger; rather it may be the case that anything that stimulates the immune system can act in this role, this would correlate with the wide variety of infectious agents mooted as triggers, and indeed with the more controversial association with vaccines.
GCA may present with a variety of different clinical phenotypes (Figure 1). In the past the focus has predominantly been on the classic cranial GCA phenotype with limited recognition of other potential presentations. The phenotypes may overlap with patients presenting with features of more than one simultaneously or in succession. Cranial GCA typically presents with unilateral or bilateral temporal headache. Headache is of course one of the most common clinical presentations and there is a wide differential. Scalp, and more specifically focal temporal artery tenderness is frequently present. The most specific clinical feature of cranial GCA is jaw claudication. Jaw claudication present similarly to intermittent claudication in the legs. There is, at least initially, no pain at rest, pain develops with use (typical chewing), to the extent that it frequently limits eating. Cessation of the provoking chewing activity will lead to symptom resolution and the ability to resume chewing until pain subsequently returns. This process is the basis for the “chewing gum test” in GCA, where the patient is offered gum, the chewing of which can precipitate claudication. Visual complications are the most feared outcome in cranial GCA. Unfortunately they remain common, affecting 20% of patients. Our treatment
approach in GCA has proven very effective in preventing ischaemic complications once the diagnosis has been made, but unfortunately can have little impact in the development of these prior to diagnosis, and this now represents the vast majority of visual issues we see in GCA. Anterior ischaemic optic neuropathy is the most common permanent visual manifestation in GCA and unfortunately almost always results in irreversible blindness in the affected eye. If prompt intervention is not taken, this may spread to effect the contralateral eye with devastating results. In some patients this permanent vision loss can be preceded by amaurosis fugax or other temporary vision loss type events, and recognition and intervention at this point may prevent permanent vision loss. Other less common visual manifestations may occur, including diplopia due to cranial nerve palsies, or homonymous hemianopia due to stroke. Polymyalgia rheumatica (PMR) is another rheumatic disease entity characterised by bilateral proximal arm and leg, as well as neck, stiffness with early morning predominance. While it is still debated, PMR and GCA are likely two ends of the spectrum of a single disease process. This is supported by shared pathogenic mechanisms, demographic associations, treatment responses, and particularly by the frequent co-occurrence of the two – 50%
