A case of 1-month-old female infant delaying peritoneal dialysis introduction by low-potassium anti-allergic formula treated with sodium polystyrene sulfonate.

The 8806H formula is the only renal formula available for pediatric patients with chronic kidney disease in Japan. A 1-month-old female infant could not be administered 8806H because of milk allergy. Administration of low-potassium anti-allergic formula treated with sodium polystyrene sulfonate maintained adequate serum potassium levels, and introduction of peritoneal dialysis could be delayed. The patient had severe renal dysfunction secondary to bilateral hypoplastic and multi-cystic kidneys. Although she received the 8806H formula, this product was switched to hydrolyzed casein formula because she developed allergy to 8806H at 28 days of age, which led to hyperkalemia. We initiated treatment with sodium polystyrene sulfonate at 40 days of age to lower the potassium concentration in milk, which prevented hyperkalemia and maintained the patient's nutritional status to ensure appropriate increase in body weight. We monitored electrolyte levels in milk and confirmed reduction in potassium levels before feeding. Although such condition is rare and there are few reports of potassium reduction in anti-allergic formulas, this strategy may be useful for pediatric patients with renal insufficiency who cannot be treated with renal formulas because of milk allergy.