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Idiosyncratic reactions to phenytoin

N G Powers, S H Carson

    Clinical Pediatrics
    |March 1, 1987
    PubMed

    Insights

    Pediatric patients on phenytoin may experience severe idiosyncratic reactions, including fever, rash, and hepatitis. Early recognition and drug discontinuation are crucial to prevent life-threatening outcomes.

    Area of Science:

    • Pediatric Pharmacology
    • Clinical Toxicology
    • Dermatology

    Background:

    • Phenytoin is a widely used antiepileptic drug in pediatric populations.
    • Idiosyncratic drug reactions can present with diverse and severe clinical manifestations.
    • Prompt identification of adverse drug events is critical for patient safety.

    Observation:

    • A case report and literature review identified 17 pediatric patients (2.5-21 years) with phenytoin-induced idiosyncratic reactions.
    • Common symptoms included fever (82%), rash (94%), lymphadenopathy (94%), and hepatitis (94%).
    • Eosinophilia was noted in 76% of cases, suggesting an immune-mediated process.

    Findings:

    • The observed constellation of symptoms frequently mimics common pediatric infections.
    • Hepatitis and significant systemic inflammation are key features of this reaction.
    • High prevalence of rash, fever, lymphadenopathy, and hepatitis highlights the severity.

    Implications:

    • Pediatricians must maintain a high index of suspicion for phenytoin hypersensitivity in patients presenting with these symptoms.
    • Early discontinuation of phenytoin is essential to avert severe complications and potential mortality.
    • This reaction underscores the importance of pharmacovigilance in pediatric epilepsy management.

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