A Case of Large Vessel Giant Cell Arteritis Presenting With Cough and Diagnosed Using an FDG-PET Scan

Giant-cell arteritis (GCA) is a type of vasculitis characterised by the presence of granulomas. It is the predominant form of systemic vasculitis in adults and primarily affects the larger arteries in individuals aged ≥ 50 years. GCA affects the major arteries, such as the aorta and its branches, particularly the outer branches of the external carotid artery. Signs and symptoms can be categorised into cranial, extracranial, and systemic manifestations. Patients with headaches, jaw claudication, and vision disturbances usually have extracranial branches of the external carotid artery. Aside from being the prevailing manifestation of GCA, our primary concern regarding this variant is the potential for irreversible vision loss if not properly identified and addressed. Conversely, the GCA can also affect other major blood vessels such as the aorta. Here, we present the case of a 70-year-old Caucasian female patient with cranial GCA who had experienced a temporal headache three years prior. The patient was successfully treated with prednisolone, which was gradually reduced to a very low level with the assistance of methotrexate. Recently, the patient presented with a dry cough that lasted for two months and elevated inflammatory markers. After thorough research, it was determined that there was no evidence of infection, including atypical infections, and that no abnormalities were found in the lungs. Ultimately, via an 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan, the patient was diagnosed with large vessel giant cell arteritis (LV-GCA). This impacted the aorta, carotid arteries, and subclavian arteries. The patient experienced notable improvement in her cough and a reduction in inflammatory markers after receiving a high dosage of oral prednisolone. This case exemplifies the unusual manifestation of LV-GCA and verifies that recurring symptoms may differ from the original presentation. While dry cough is not commonly listed as a symptom of LV-GCA, it can be present as a manifestation or the sole presentation in certain patients, particularly when inflammatory markers are consistently high and there is no pulmonary disease.