Giant cell arteritis with normal inflammatory markers

Abstract

Editor, G iant cell arteritis (GCA) is a neuro-ophthalmological emergency given the risk of permanent, severe visual loss if left untreated (Hayreh et al. 1998a). We present a rare case of biopsy-proven GCA with normal inflammatory markers at first presentation. A 74-year-old woman was referred to us with a 2 month history of rightsided temporal headaches. She had no relevant past medical history but her sister suffered from polymyalgia rheumatica. The headaches occurred almost daily and often lasted several hours. She reported no visual symptoms, jaw claudication or other classical symptoms of polymyalgia rheumatica or GCA. Her Snellen visual acuity was 6 ⁄ 6 in both eyes and ocular examination was entirely normal. Her temporal arteries on both sides were pulsatile, non-tender and normal in appearance. Inflammatory markers were requested to rule out GCA; these were normal, with an erythrocyte sedimentation rate (ESR) of 30 mm ⁄hr and a C-reactive protein (CRP) <5 mg ⁄L. The patient was therefore discharged from clinic. She re-presented 6 months later, still complaining of right-sided temporal headaches, but over the past 3 months she had also become aware of scalp tenderness, transient episodes of jaw ache and feeling tired. She again denied any visual disturbance, and ocular examination was unremarkable. However, her right temporal artery was now thickened, although non-tender and still pulsatile. Inflammatory markers were raised with an ESR of 96 mm ⁄hr and a CRP of 18 mg ⁄L. Other routine bloods, including a full blood count, were normal. She was started on 60 mg of oral prednisolone, and a right temporal artery biopsy (TAB) showed unequivocal histological features of GCA. Her symptoms resolved completely on steroids and, a year later, there has been no disease recurrence as her treatment has been tapered down. This case illustrates an atypical, insidious presentation of GCA. The recent onset of unilateral temporal headaches, its persistence and the subsequent development of other clinical features indicate an evolution of the underlying pathological process. The normal inflammatory markers and absence of other systemic and ocular symptoms could be explained by localized involvement of her temporal arteries. Temporal headache is the most common clinical symptom of GCA and is reported by up to 90% of patients (Rahman & Rahman 2005). In Jonasson’s series of 124 biopsy-proven cases, a higher ESR and more generalized systemic features were also associated with longer disease duration (Jonasson et al. 1979). Although an ESR is frequently requested by clinicians in order to rule out this condition, a normal level has been reported in 5–30% of patients with GCA (Rahman & Rahman 2005). In Hayreh’s series of 363 patients who had TAB for suspected GCA, CRP was more sensitive (100%) than ESR (92%) in detecting GCA, and a combination of ESR and CRP gave the best specificity (97%) (Hayreh et al. 1997). It is also well established that patients with occult GCA can have significantly lower inflammatory markers compared to those with the more classical systemic features (Hayreh et al. 1998b). Recently, Poole and colleagues presented a unique case of occult GCA with normal ESR and CRP (Poole et al. 2003). Their patient had transient episodes of monocular visual loss and evidence of ocular ischaemia with ophthalmoplegia, cotton wool spots and a markedly delayed choroidal perfusion on fluorescein angiography. These findings raised the possibility of GCA, which was confirmed with a positive TAB. As in our case, this highlights the importance of TAB as the gold-standard diagnostic test in GCA since inflammatory markers can be normal if the disease process is at an early stage, there is only localized arteritis or there is an inability to mount an acute-phase serologic response. GCA is a heterogeneous disease with a wide range of clinical manifestations. It remains a challenging diagnosis, requiring a high index of clinical suspicion and a low threshold for TAB.