Introduction: Drug-induced lupus (DILE) involves the development of clinical features of systemic lupus erythematosus secondary to medication use. Multiple drugs can cause DILE through mechanisms that are largely unknown but thought to be related to chemical structure. The pathogenesis of drug-induced lupus is thought to involve a combination of genetic predisposition, drug biotransformation, and epigenetic dysregulation. While other antiepileptic drugs (AEDs) have been reported to cause DILE, valproic acid (VPA) has not been commonly documented in the literature. A systematic literature review identified 14 cases of VPA-induced DILE since 1990, with only two described in children. Most patients presented with fever and polyarthralgia, while 2 were reported to have pleural effusions. We present a patient diagnosed with DILE secondary to VPA, following the development of a pericardial effusion and multiple pleural effusions.
Description: The patient is a 17-year-old male with spinal muscular atrophy, progressive myoclonic epilepsy, intractable seizures without status epilepticus, and tracheostomy/ ventilator dependence, who presented with acute on chronic respiratory failure. He was persistently tachycardic and unresponsive to fluid resuscitation, prompting an echocardiogram, which revealed a large pericardial effusion. A pericardial drain was placed, and 720 mL of fluid was removed. He was then found to have a left-sided pleural effusion. A thoracotomy tube was placed and later removed, after which the pleural effusion reaccumulated. Cell counts from the pleural fluid showed eosinophilia, suggesting VPA as the likely cause of the serositis. An anti-histone antibody test was obtained and positive. With a diagnosis of VPA-induced DILE, the drug was discontinued, he was transitioned to a different AED without recurrence of the effusions.
Discussion: While medications are essential for managing complex conditions, it is important to remain vigilant about potential side effects. In this case, the recurrence of effusions prompted a broader differential. After a thorough review of the patient's medications, VPA was suspected to be the underlying cause of his symptoms. Given the importance of VPA in his seizure management, it was also necessary to confirm the diagnosis before discontinuing the medication.
