000876 - Pustular Eruption Following Oral Iron Supplementation: A Drug Eruption Confirmed by Lymphocyte Transformation Test

Background

Pustular drug eruptions associated with oral iron preparations are rarely reported in the literature. Combined iron supplements containing multiple micronutrients may complicate the identification of the culprit agent.

Case Report

A 20-year-old male patient had been using an oral combined preparation containing iron, zinc, folic acid, and vitamin C for 10 days without any adverse effects. After the 11th dose, taken at night, erythematous papulopustular lesions appeared on the arm the following morning and rapidly spread to the trunk and extremities. No mucosal involvement or systemic symptoms were observed. Laboratory evaluation revealed no elevation in liver enzymes and no peripheral eosinophilia.

The patient discontinued the medication for 1–2 days; however, as the lesions did not regress, he presented to the emergency department, where antihistamine treatment (cetirizine) was initiated. No new lesions developed after treatment, but the existing eruptions persisted. Dermatology consultation supported the diagnosis of a drug eruption.

To confirm the diagnosis, a lymphocyte transformation test (LTT) was performed and yielded a positive result for the suspected oral preparation. Based on these findings, avoidance of the combined preparation was recommended, and the use of single-ingredient or alternative iron formulations was advised if iron replacement therapy became necessary.

Conclusion

Pustular drug eruptions related to oral iron supplementation are extremely rare. This case highlights a pustular drug eruption following the use of a combined iron preparation, with diagnostic confirmation by LTT. In patients requiring iron replacement, the use of single-component or alternative preparations may represent a safer approach to prevent similar hypersensitivity reactions.