Towards self-monitoring and self-treatment in phenylketonuria--a way to better diet compliance.

It has been a long established principle in the treatment of diabetes that the patient or his/her family is responsible for day-to-day monitoring of metabolic control. It is believed that this concept should also now be applied in phenylketonuria. At present, self-monitoring of blood phenylalanine still requires assaying the phenylalanine concentration in capillary blood obtained by finger-stick sampling at home, via mailing to a nearby laboratory. Frequently and rapidly obtained data can guide the patient to adjust dietary phenylalanine intake, provided he and his family have been informed in detail about the disease and trained in practical diet competence. Teaching programmes for patients are to be promoted. A home-monitoring device for blood phenylalanine is at the development stage.