Bilirubin, copper-porphyrins, and the bronze-baby syndrome.

Controlled in vitro spectroscopic measurements reveal that bilirubin does not photosensitize the degradation of copper-porphyrins, as has been proposed for the mechanism of the bronze-baby syndrome, an uncommon side-effect of phototherapy. Calculations also show that copper-porphyrins are unlikely to cause the "bronzing." In conclusion, the copper-porphyrin hypothesis is photochemically implausible.