Milk allergy and vitamin D deficiency rickets: a common disorder associated with an uncommon disease

BackgroundCow's milk allergy is one of the most common allergies in infancy. It has an excellent prognosis since most cases resolve by 4 years of age. The complications associated with milk allergy include delayed growth and atopic conditions, such as asthma, allergic rhinitis, atopic dermatitis, and other food allergies.ObjectiveTo report a case of vitamin D deficiency rickets in a 2-year-old boy with cow's milk allergy.MethodsWe describe a patient with clinical and biochemical evidence of rickets, including decreased serum calcium, phosphate, and 25-hydroxy vitamin D levels and an elevated alkaline phosphatase level. A dietary history revealed the prolonged absence of dietary vitamin D because the child did not tolerate cow's milk. Skin prick testing and measurement of specific IgE to cow's milk were performed to determine whether there was an allergy to cow's milk.ResultsResults of skin prick testing and measurement of specific IgE to cow's milk confirmed an IgE-mediated sensitivity to cow's milk. Introduction of appropriate supplementation into the child's diet resulted in complete resolution of his symptoms.ConclusionsThis case emphasizes that the management of cow's milk allergy involves strict avoidance of the allergenic food while also ensuring that essential dietary requirements are met. A dietary history is crucial at all pediatric visits, and inquiry about supplementation of vitamins and minerals is important, especially in children with food allergies.