Giant cell arteritis associated with acute Q fever - A case report

Area of Science:

• Infectious Diseases
• Rheumatology
• Pathology

Background:

• Q fever is a globally prevalent zoonotic illness caused by Coxiella burnetii.
• While typically presenting with flu-like symptoms, pneumonia, or hepatitis, Q fever can occasionally mimic autoimmune disorders.
• Giant cell arteritis (GCA) is a systemic vasculitis primarily affecting large and medium-sized arteries.

Observation:

• A 69-year-old male presented with prolonged fever and pneumonitis, initially suspected to be an autoimmune condition.
• Temporal artery biopsy was performed, revealing findings consistent with giant cell arteritis.
• The patient's presentation mimicked an autoimmune disease, prompting a differential diagnosis investigation.

Findings:

• Polymerase chain reaction (PCR) testing on the temporal artery biopsy specimen was positive for Coxiella burnetii DNA.
• This molecular evidence directly linked the patient's symptoms and GCA findings to an infectious etiology.
• The case demonstrates an unusual presentation of acute Q fever mimicking giant cell arteritis.

Implications:

• This finding suggests that Coxiella burnetii infection should be considered in the differential diagnosis of biopsy-proven giant cell arteritis.
• Identifying an infectious cause has significant implications for patient management and treatment strategies.
• Further research may elucidate the role of infectious agents in the pathogenesis of certain vasculitides.