Background: The development of hypophosphataemic rickets in infants fed with the elemental formula (EF) Neocate® has been recently reported. We present seven cases of exclusively Neocate-fed babies who developed hypophosphataemic rickets.
Presenting problem: Three patients (P1,3,4) had incidental findings of rickets on chest X-rays, two (P2,6) developed leg deformities and rickets was confirmed on X-rays, and two (P5,6) presented with femur fractures. Patient 7 was found to have low phosphate concentrations on routine blood testing and was further investigated. All patients (age 5 months 3.2 years) were exclusively fed on Neocate at presentation and had normal serum calcium and parathyroid hormone concentrations, raised alkaline phosphatase and hypophosphataemia. Vitamin D deficiency and renal phosphate wasting were excluded (Table 1).
Clinical management: Following exclusion of other causes of rickets, reduced intestinal phosphate absorption due to EF was considered. Patients 16 were treated with phosphate supplements after diagnosis of rickets. Patient 6 was previously on long term steroids and received one course of bisphosphonates after the fracture. Formula was changed eventually in all patients and phosphate concentrations normalized after 1 week-4 months. Clinical and/or radiological improvement of rickets was noted in P2,3,4. No X-ray confirmation of improvement is available so far in the others.
|Patient 1||Patient 2||Patient 3||Patient 4||Patient 5||Patient 6||Patient 7|
|Diagnosis||Presumed cows milk allergy||GORD, cows milk intolerance||Pierre-Robin Syndrome, cleft palate, CP, GORD, NJ fed||CHARGE syndrome, GORD, PEG fed||FTT, GORD, PEG-NJ fed||SCID, BMT, GVHD on steroids, refusing feed||SOD, GORD, 8q12.3del, tectal plate glioma, NJ fed|
|Age at presentation||6 months||10 months||11 months||18 months||9 months||3 years 2 m||5 months|
|Exclusively on Neocate before presentation (duration)||3 months||10 months||>8 months||>6 months||5 months||15 months||5 months|
|Abbreviations: GORD: gastro-oesophageal reflux disease; CP: cerebral palsy; NJ: naso-jejunal; PEG: percutaneous endoscopic gastrostomy; FTT: failure to thrive; SCID: severe combined immunodeficiency; BMT: bone marrow transplant; GVHD: graft versus host disease; SOD: septo-optic dysplasia;.NA: not available.|
Discussion: The fact that serum phosphate improved following weaning of Neocate supports its role in the causation of hypophosphataemia; poor intestinal absorption of phosphate is the assumed mechanism in infants exclusively fed with Neocate. Clinicians should exercise caution in the use of EF in the absence of clear clinical indications. Infants who are being exclusively fed on Neocate should have close clinical and biochemical monitoring of bone profile, in accordance with existing guidance.
Disclosure: The authors declared no competing interests.