P040 An unusual case of giant cell arteritis
Authors: Ellis Jessica , Austin Keziah , Emerson Sarah 
Published: April 2021

Abstract
Background/Aims
A 49-year-old female of Nepalese heritage was referred with right-sided headache, scalp tenderness, and a painful swelling overlying the right temple. She denied any visual or claudicant symptoms but felt systemically unwell with a fever. There were no symptoms suggestive of an inflammatory arthritis, underlying connective tissue disease or vasculitis. She was normally fit and well with no past medical history. She did not take any regular medications and denied using over the counter or illicit drugs or recent travel. On review she had a low grade fever. There was a large tender, erythematous swelling overlying the right temple. Bilaterally the temporal arteries were palpable and pulsatile. Peripheral pulses were normal with no bruits. There was no evidence of shingles (HSV) or local infection. Full systemic examination revealed no other abnormalities. Laboratory tests showed: PV 2.56, CRP 101, total white cell count 14.38 (eosinophils 0.4), albumin 33, Hb 115. Urine dip was normal. Renal function, liver function and immunoglobulins were normal. ANCA was negative. Hypoechogenicity surrounding the right frontal branch of the right temporal artery was seen on ultrasound. There were no discrete masses suggestive of cysts, abscess or tumours. Temporal artery biopsy confirmed the presence of vasculitis; histology demonstrated transmural lymphohistiocytic inflammation, disruption of the elastic lamina and intimal proliferation. Prednisolone was started at 40mg daily. Four weeks after initially presenting she was asymptomatic and her inflammatory markers had normalised.
Methods
The case is discussed below.
Results
Temporal arteritis, or GCA, is primarily a disease of older adults; with age 50 often used as an inclusion criteria, and is more common in Caucasian populations. Limited reports exist of GCA in younger cohorts, but these are rare. An important differential in younger patients, such as ours, is juvenile temporal arteritis. This rare localised vasculitis affects almost exclusively the temporal artery. It is typically a disease of young males, who present with non-tender temporal swelling. Systemic symptoms are unusual and inflammatory markers are normal. Clinical or laboratory evidence of organ involvement, peripheral eosinophilia or fibrinoid necrosis on histology should prompt consideration of an AAV or PAN. Incidence of GCA increases in correlation with Northern latitude, with highest rates reported in Scandinavian and North American populations. GCA is rare in Asian populations. Higher diagnostic rates in countries where physicians have increased awareness of GCA proposed as an explanation for this difference; however differences in incidence are still observed between Asian and Caucasian populations presenting to the same healthcare providers.
Conclusion
GCA is an uncommon diagnosis in younger and non-Caucasian patients. Thorough investigation through ultrasound and biopsy helped increase our diagnostic confidence in this unusual case. Rheumatologists must be alert to atypical presentations in order to deliver prompt and potentially sight-saving treatment.
Disclosure
J. Ellis: None. K. Austin: None. S. Emerson: None.