Anxious Hyperventilation and Hyperreflexia: Hypophosphatemia Diagnostic Clues
Ten-year-old boy admitted with headache, transitory muscle spasm of the extremities, mental confusion and shortness of breath after a stressful event. Blood tests revealed hypophosphatemia (serum phosphate 1.4 mg/dL). Diagnosis was acute hypophosphatemia due to hyperventilation, as a result of redistribution of serum phosphate. During hospitalization, he received oral phosphate supplementation and attained normal levels of serum phosphate. Further investigation revealed 25-hydroxyvitamin D deficit and supplementation was administered. He had no more similar episodes. The authors present this case to alert to the possibility of occurrence of hypophosphatemia caused by hyperventilation in a child with a predisposing vitamin D deficiency.