[Drug induced eosinophilic pleural effusion].

Area of Science:

• Pulmonology
• Neurology
• Clinical Pharmacology

Background:

• Drug-induced hypersensitivity reactions (DIHRs) are a significant concern, particularly with widely used medications like central nervous system drugs.
• The lungs are a common target organ for DIHRs, presenting with diverse clinical manifestations.
• Anticonvulsant medications, while essential for managing epilepsy, carry a risk of adverse pulmonary events.

Observation:

• A 40-year-old male with a history of epilepsy presented with pleuritic chest pain and dry cough.
• Diagnostic workup revealed left-sided pleural effusion with eosinophilic exudate and significant blood eosinophilia.
• Other potential causes, including infection, infarction, trauma, and parasitic infestations, were systematically excluded.

Findings:

• A diagnosis of exclusion pointed towards a hypersensitivity reaction to anticonvulsant medications, specifically carbamazepine and sodium valproate.
• Discontinuation of the suspected anticonvulsants and initiation of alternative treatment (lamotrigine and levetiracetam) led to the resolution of blood eosinophilia and partial improvement of pleural effusion.
• Complete resolution of pleural effusion and normalization of blood counts were observed during follow-up, confirming the favorable outcome after treatment modification.

Implications:

• This case highlights the importance of considering DIHRs in patients presenting with unexplained pulmonary symptoms and eosinophilia, especially those on long-term anticonvulsant therapy.
• Prompt recognition and withdrawal of the offending agent are crucial for managing drug-induced lung injury.
• The findings underscore the need for a multidisciplinary approach involving neurologists and pulmonologists in diagnosing and managing complex adverse drug reactions.