Acquired Zinc Deficiency in Only the Third Child Due to Low-Zinc Breast Milk

Abstract

A 7-month-old breast-fed infant presented to our hospital for perioral and buttock eczematoid lesions and erosions. He was a full-term infant and the third child. He had been treated with topical corticosteroids for the skin lesion for two months, but his symptoms did not improve. Diarrhea and hair loss on the occipital region were also observed. His siblings (9 years old and 7 years old) had also been completely breast-fed, but no similar symptoms had been observed. The serum zinc concentration in the patient and the zinc concentration in the breast milk of the mother (35 years old) were both low. We performed a sequence analysis of the SLC30A2 gene using a peripheral blood sample after obtaining written informed consent from the mother; however, no gene mutation was detected. The patient was finally diagnosed with zinc deficiency due to low-zinc milk. The diarrhea improved promptly after starting 0.1 g of polaprezinc (containing about 3.4 mg zinc) daily, and the serum zinc concentration in the patient was within the standard value 2 weeks later. The skin lesions began to improve. One month later, uniform hair growth was observed at the occipital region. With the start of baby food, the polaprezinc was tapered and discontinued six months later. Following the discontinuation, no recurrence of the skin lesion was observed in the next year.