Abnormal tryptophan pyrrolase and amino acids related to melanogenesis in vitiligo.

A comparison of the serum tyrosine, DOPA, tryptophan, tyrosinase and tryptophan pyrrolase levels of vitiliginous patients with those of normal subjects show abnormalities in all these parameters. As the clinical diagnosis of vitiligo may be made without difficulty, these parameters appear to be of little diagnostic value in vitiligo. But they may be considered as additional biochemical parameters in vitiligo.