2576

ZINC DEFICIENCY IN BREAST-FED PREMATURE INFANTS: A POORLY RECOGNISED CONDITION

Kay Stephen, James Doery, Kah Tzay Low, Susan Feng, Victor Yu

Department of Pathology & Immunology and Department of Pediatrics, Monash University, Melbourne, Australia

A retrospective search of the pathology infant database revealed 10 cases of biochemical zinc deficiency (serum zinc＜10 umol/L) between 1995 and 2000, All 10 babies were premature with gestational ages of 24-29 weeks. An associated erythematous rash was first documented at between 14-97 days of age (mean 51). Seven babies had been on exclusive breast-feeding for between 9-65 days; the other 3 were on a combination of breast milk, supplemented with total parenteral nutrition (TPN) when the rash first appeared, Further reviews of the medical records revealed additional problems with both diagnosis and clinical management concerning the rash and associated zinc deficiency. There was a delay of 0-67 days (mean 25) between the onset of the rash and the first serum zinc measurement. During this interval a range of remedies were tried including topical antifungals, antibiotics and zinc creams, none of which had clinical benefit. Furthermore, following detection of low serum zinc there was prompt oral zinc supplementation in only 6 babies, a delay of 2-3 weeks in 2 others, but no zinc replacement at all in the remaining 2 babies, Oral zinc supplementation produced a rapid resolution of the rash in those babies given oral zinc sulfate. A total of 34 zinc measurements on these 10 patients revealed at least 8 results in the very high range of＞50 umol/L, in the absence of any oral zinc supplements; two results were＞400 umol/L. It became clear that contamination of capillary blood samples with skin zinc originating from topical zinc containing creams, is a potential confounding factor in confirming zinc deficiency. In conclusion, and within the constraints of a retrospective analysis, premature breast-fed babies appear to be at increased risk of clinical zinc deficiency, but a prospective study is required to more accurately define the incidence of clinical and subclinical zinc deficiency in this at risk population.