Early Intervention by a Ward Pharmacist for the Hyperzincemia Caused by Zinc Oxide Ointment in a Infant with Diaper Dermatitis: A Case Report

Although zinc oxide ointment is commonly used to treat diaper dermatitis in infants, there exists limited evidence of pharmacists suspecting hyperzincemia due to zinc oxide ointment and early intervention for mitigation of severity. This case study is female infant who was born at 27 weeks and 1 d of gestation and weighing 542 g. On postnatal 49 d, the serum zinc concentration was 65 µg/dL. Thereafter, treatment with oral zinc acetate hydrate (2 mg/kg/d) began on 56 d for ameliorating hypozincemia. Zinc oxide ointment was administered on 86 d as a treatment for diaper dermatitis. Despite of attaining hyperzincemia (427 µg/dL), treatment with zinc acetate hydrate and zinc oxide ointment continued because diarrhea and nausea had not developed. On 105 d, the serum zinc concentration was 199 µg/dL and the dermatitis conditions showed a marked improvement. Consequently, the pharmacist considered that zinc oxide ointment might have contributed to the hyperzincemia and consulted with the physician. Subsequently, both the zinc acetate hydrate and zinc oxide ointment were discontinued. Although zinc acetate hydrate was restarted on 114 d, serum zinc concentration was 101 µg/dL on 128 d. The Naranjo Adverse Drug Reaction Probability Scale score was 9 points, which is categorized as "definitive." Administration of zinc oxide ointment to diaper dermatitis with decrease skin barrier may have increased percutaneous absorption of zinc, resulting hyperzincemia. The pharmacist may be able to conduct early intervention for hyperzincemia by monitoring not only serum zinc concentration but also changes in the dermatitis conditions in infant patients.