Abstract
A 1-year-7-month old boy was referred to our hospital suspected of nutritional rickets. He had received a diagnosis of food allergy by a dermatologist at 4 months old. The mother had eliminated egg, cow's milk, and wheat from her diet so that the proteins could not being passed through the breastmilk. He had taken an elimination diet in which egg, cow's milk, and wheat were removed. Around at 1 year old, urticaria had developed and he had gotten fretful after fish intake. As IgE antibodies against fish had showed positive, fish intake had been restricted. At the first visit, radiographic images of lower legs showed little rickets changes. Blood examinations revealed the marked elevation of levels of alkaline phosphatase and parathyroid hormone, while serum concentrations of calcium and phosphate were within normal range. At 1 year 8 months old, he suddenly showed a drastic drop in running ability and blood exam revealed the low level of 25(OH)D, which led to the definitive diagnosis of vitamin D deficiency rickets. Restriction of fish that are the main sources of vitamin D with breast-feeding would cause vitamin D deficiency rickets though he had gotten enough sun exposure. This case indicated that we should take note of rickets even without any symptoms in a food allergy patient who need restriction diet.
