BACKGROUND: Neonatal blue light phototherapy (NBLP) has been widely and successfully
used for the treatment of neonatal jaundice to reduce the plasma concentration of
bilirubin and, hence, to prevent kernicterus. Only a few and controversial data are
available in the literature as to how NBLP influences melanocytic nevus development.
OBJECTIVE: Our goal was to conduct a twin study with the aim of better understanding
the role of NBLP in melanocytic nevus development. We also investigated the roles
of other environmental and constitutional factors in nevus formation. METHODS: Fifty-nine
monozygotic and dizygotic twins were included in this cross-sectional study. One of
the twin members received NBLP, and the other did not. A whole-body skin examination
was performed to determine the density of melanocytic skin lesions. The prevalence
of benign pigmented uveal lesions was evaluated during a detailed ophthalmologic examination.
A standardized questionnaire was used to assess data relating to constitutional, sun-exposure,
and other variables. To search for possible gene-environmental interactions involved
in the appearance of pigmented lesions, the melanocortin 1 receptor variants and the
I439V polymorphism of histidine ammonia-lyase genes were also determined in the enrolled
twins. RESULTS: NBLP was associated with a significantly higher prevalence of both
cutaneous and uveal melanocytic lesions. No association was found between the examined
gene polymorphisms and the number of pigmented alterations in the examined study group.
CONCLUSIONS: Our data suggest that NBLP could well be a risk factor for melanocytic
nevus development. Phototherapy with blue-light lamps is a standard and essential
therapeutic modality in neonatal care; therefore, additional in vivo and in vitro
studies are necessary to establish its potential long-term adverse effects.
