[Pleural effusion revealing Horton's disease].

Area of Science:

• Rheumatology
• Pulmonology
• Internal Medicine

Background:

• Pulmonary involvement is an uncommon manifestation of Horton's disease (also known as giant cell arteritis).
• Reported pulmonary findings include interstitial infiltrates, vasculitis, nodules, and granulomas, with pleural effusion being exceptionally rare.
• The diagnosis of Horton's disease typically relies on clinical symptoms, elevated inflammatory markers, and temporal artery biopsy.

Observation:

• A 65-year-old male presented with right-sided pleural effusion.
• Clinical symptoms included headaches, ocular involvement, and general signs suggestive of Horton's disease.
• Temporal artery biopsy confirmed giant cell arteritis.

Findings:

• Despite a negative etiological workup for the pleural effusion, it was attributed to Horton's disease.
• The patient's condition improved favorably with systemic corticosteroid therapy.

Implications:

• Pleural effusion, though rare, can be an initial presenting symptom of Horton's disease.
• Diagnosis may rely on clinical suspicion and response to treatment due to a lack of specific biological or histological markers for pleural involvement.
• This case highlights the importance of considering Horton's disease in the differential diagnosis of unexplained pleural effusion, particularly in older adults with suggestive symptoms.