Exanthematous Drug Eruption to Intravenous Iron: A Case Report

The authors present a rare case of an exanthematous drug reaction to intravenous iron. Exanthematous drug eruptions, also called morbilliform or maculopapular drug rashes, can occur in first-time drug exposures and represent a subtype of delayed-type IV hypersensitivity reactions.  This patient is a 49-year-old female with a history of iron deficiency anemia and hypothyroidism who presented to the emergency department after experiencing a diffuse whole-body maculopapular rash following ferumoxytol 510 mg intravenously received once two days prior to her presentation. A clinical examination was suspicious of an exanthematous drug eruption. The patient was treated with methylprednisolone 40 mg intravenously twice a day for three days, followed by prednisone 40 mg orally twice a day for two days with a steroid taper upon discharge. The patient's rash resolved within five days of steroid treatment. There is a high global prevalence of iron deficiency anemia for which intravenous iron replacement may be required. However, there is limited research addressing its adverse effects, particularly those that include delayed hypersensitivity reactions. This paper aims to alert healthcare professionals of a rare type of delayed hypersensitivity reaction to intravenous iron to better guide management in the clinical setting.