The comments of Koch et al are well taken. They further remind us of the rarity of acrodermatitis enteropathica—like illness as a complication of amino-acid imbalance in maple syrup urine disease and the fact that the more common complication is a periorificial dermatitis.
Since the skin is one of the tissues that turns over most rapidly, it is not surprising that it would be one of the first tissues to be affected by an amino-acid imbalance. It certainly seems possible that amino-acid imbalance as a consequence of secondary effects on cellular transport may be as important as a frank amino-acid deficiency. We believe that our patient probably represented the far spectrum of severe involvement with amino-acid imbalance.
Different biochemical abnormalities in patients with maple syrup urine disease with inadequate dietary intake (ie, isolated deficiency of isoleucine or of the three branched-chain amino acids1 or an abnormal leucine-isoleucine ratio),