Cutaneous and neurologic manifestations of biotinidase deficiency

A male newborn with no obstetric or familial antecedents, except that his p arents were cousins, developed hypotonia, lethargy, and feeding problems fr om birth. Analysis revealed a marked metabolic acidosis and hyperammonemia. Three weeks later, he was admitted to hospital in order to receive parente ral nutrition and to undertake a study for metabolic diseases. The boy did not improve in spite of the use of parenteral nutrition and beg an to present with inspiratory strider and tachypnea. One week later, he pr esented with an erythematous scaling eruption, which was especially intense in the lumbosacral region (Figs 1a, b). The scalp was only slightly affect ed. Laboratory findings were compatible with biotinidase deficiency diagnosed b y demonstrating absent enzyme activity. His parents were also studied and t hey were found to have partial biotinidase deficiency (30% of enzyme activi ty). After 37 days of life, the baby was given a treatment consisting of 20 mg o f biotin per day intravenously. Biochemical and neurologic alterations impr oved quickly. Meckel's diverticulum and a duodenal membrane were detected at the second m onth of life after a gastroduodenal survey, and both were operated on. The skin lesions did not improve, however, and intravenous biotin had to be inc reased to 40 mg/day. The eruption disappeared after 10 days. On his first birthday, he remained asymptomatic with 40 mg of oral biotin.