Biotin Deficiency in an Infant Fed with Amino Acid Formula

This study reported a case of biotin deficiency in a 5-month-old Japanese infant who was fed only an amino acid formula after being diagnosed with dyspepsia. The infant exhibited symptoms such as alopecia and scaly, erythematous dermatitis around body orifices. Despite normal zinc and biotinidase levels, the infant had low serum and urine biotin levels and elevated urinary excretion of certain organic acids. Treatment with 1 mg of daily oral biotin supplementation led to significant improvement in skin condition and hair growth, as well as the resolution of organic aciduria. The study highlighted that skin manifestations are crucial for diagnosing biotin deficiency and that urinary excretion of biotin and organic acids are more sensitive indicators of biotin deficiency than serum biotin levels.